In House Electrics, Where Do I Go From Here?

[Crossy]

I would change the Miniature Circuit Breakers (MCB) for all circuits except lighting circuits to Residual Current Breaker with Overload protection (RCBO), and also replace the surge arrester with an unit from Dehn (the specialist company in that field) that protects your application up to 40kA. 15kA is not much of a protection really in case of a lighting strike.

In which case you won't need the RCD incomer, a regular 2-pole 63A MCB will do the job.

Whilst it will improve discrimination in the event of a ground fault it won't actually improve protection against shock. It will certainly blow the budget away.

Up to U.

[eraymos]

I would change the Miniature Circuit Breakers (MCB) for all circuits except lighting circuits to Residual Current Breaker with Overload protection (RCBO), and also replace the surge arrester with an unit from Dehn (the specialist company in that field) that protects your application up to 40kA. 15kA is not much of a protection really in case of a lighting strike.

In which case you won't need the RCD incomer, a regular 2-pole 63A MCB will do the job.

Whilst it will improve discrimination in the event of a ground fault it won't actually improve protection against shock. It will certainly blow the budget away.

Up to U.

I think I'll keep things the way they are for now. If I find out that I'm going back and forth to the CU to turn switches back on, I can always upgrade. (Then again the problem would most likely be with the appliance and not the CU???) I'm most worried about saftey factors, and that does not seem to be a problem with this set up, if everything is properly grounded. Do we agree on that?

[david96]

If you have to keep resetting an RCD you will either have a problem with nuisance tripping or you have a faulty item of electrical equipment.

With nuisance tripping the standing earth leakage current should not exceed 30% of the RCD rating in mA. For a 30ma RCD this would be 10mA. In practice in an individual residential electrical installation this is a minimal problem.

SPDs should have a minimum rating of 40kA , 8/25 microsec, 275V. protected by a MCB and connected on the load side of the main switch. This will be close to the main earthing bar at the main switchboard. DIN rail mounting SPDs have replaceable plug -in modules.

Sensitive electronic equipment may have additional protection by means of surge and spike protected power boards at the socket outlets.

You are more likely to experience the effects of an indirect lightning strike than that of a direct one on an electrical installation or the effects of HV switching on the distribution network.

You should also consider where the first socket outlet for your telephone service is to be located, this should be a RJ12 or RJ45 mounted on a flush mounting plate. You should have a twin socket outlet located adjacent, about 150mm from the telephone outlet.

The location of all switches and socket outlets should be accessible at all times and not blocked by furniture or fixtures.

[david96]

Installing a 63A 30mA RCBO as the main switch for the electrical installation and you may have problems with nuisance tripping.

It would be more advisable to install a 63A 10kA at 220V MCB as the main switch and install 2 or more 4 pole DIN RCDs. A 4 pole RCD for 3 individual circuits. Each circuit protected by a DIN MCB rated at a minimum of 3kA. The line side of the RCDs are protected by the 63A MCB.

Or, an individual RCBO for each power circuit supplying socket outlets with the 63A MCB as the main switch.

A 24 pole (module) DIN loadcentre should be the minimum.

The main switch can be a DIN type MCB and fit in the load centre.

[stgrhe]

As usual very good advices from your David. You, Elk and Crossy are indeed very helpful with your deep knowledges.

[eraymos]

If you have to keep resetting an RCD you will either have a problem with nuisance tripping or you have a faulty item of electrical equipment.

With nuisance tripping the standing earth leakage current should not exceed 30% of the RCD rating in mA. For a 30ma RCD this would be 10mA. In practice in an individual residential electrical installation this is a minimal problem.

SPDs should have a minimum rating of 40kA , 8/25 microsec, 275V. protected by a MCB and connected on the load side of the main switch. This will be close to the main earthing bar at the main switchboard. DIN rail mounting SPDs have replaceable plug -in modules.

Sensitive electronic equipment may have additional protection by means of surge and spike protected power boards at the socket outlets.

You are more likely to experience the effects of an indirect lightning strike than that of a direct one on an electrical installation or the effects of HV switching on the distribution network.

You should also consider where the first socket outlet for your telephone service is to be located, this should be a RJ12 or RJ45 mounted on a flush mounting plate. You should have a twin socket outlet located adjacent, about 150mm from the telephone outlet.

The location of all switches and socket outlets should be accessible at all times and not blocked by furniture or fixtures.

Thanks for the comments, but as for safety you do not see a problem with my set up for now? The SPD is what Square D recommends and yes, placed right after the main breaker. The telephone line is going approx. where you say but it will be awhile before that is in place.

[david96]

If you have to keep resetting an RCD you will either have a problem with nuisance tripping or you have a faulty item of electrical equipment.

With nuisance tripping the standing earth leakage current should not exceed 30% of the RCD rating in mA. For a 30ma RCD this would be 10mA. In practice in an individual residential electrical installation this is a minimal problem.

SPDs should have a minimum rating of 40kA , 8/25 microsec, 275V. protected by a MCB and connected on the load side of the main switch. This will be close to the main earthing bar at the main switchboard. DIN rail mounting SPDs have replaceable plug -in modules.

Sensitive electronic equipment may have additional protection by means of surge and spike protected power boards at the socket outlets.

You are more likely to experience the effects of an indirect lightning strike than that of a direct one on an electrical installation or the effects of HV switching on the distribution network.

You should also consider where the first socket outlet for your telephone service is to be located, this should be a RJ12 or RJ45 mounted on a flush mounting plate. You should have a twin socket outlet located adjacent, about 150mm from the telephone outlet.

The location of all switches and socket outlets should be accessible at all times and not blocked by furniture or fixtures.

Thanks for the comments, but as for safety you do not see a problem with my set up for now? The SPD is what Square D recommends and yes, placed right after the main breaker. The telephone line is going approx. where you say but it will be awhile before that is in place.

No, not with safety. the SPD should be protected with a MCB and the earth from the SPD should be run to the main earth bar, minimum 4sqmm.

Edited May 11, 2010 by david96

[eraymos]

If you have to keep resetting an RCD you will either have a problem with nuisance tripping or you have a faulty item of electrical equipment.

With nuisance tripping the standing earth leakage current should not exceed 30% of the RCD rating in mA. For a 30ma RCD this would be 10mA. In practice in an individual residential electrical installation this is a minimal problem.

SPDs should have a minimum rating of 40kA , 8/25 microsec, 275V. protected by a MCB and connected on the load side of the main switch. This will be close to the main earthing bar at the main switchboard. DIN rail mounting SPDs have replaceable plug -in modules.

Sensitive electronic equipment may have additional protection by means of surge and spike protected power boards at the socket outlets.

You are more likely to experience the effects of an indirect lightning strike than that of a direct one on an electrical installation or the effects of HV switching on the distribution network.

You should also consider where the first socket outlet for your telephone service is to be located, this should be a RJ12 or RJ45 mounted on a flush mounting plate. You should have a twin socket outlet located adjacent, about 150mm from the telephone outlet.

The location of all switches and socket outlets should be accessible at all times and not blocked by furniture or fixtures.

Thanks for the comments, but as for safety you do not see a problem with my set up for now? The SPD is what Square D recommends and yes, placed right after the main breaker. The telephone line is going approx. where you say but it will be awhile before that is in place.

No, not with safety. the SPD should be protected with a MCB and the earth from the SPD should be run to the main earth bar, minimum 4sqmm.

Can you please explain why it is unsafe? Are you then saying that if I have a RCD mainbreaker I can not have a SPD?

[david96]

If you have to keep resetting an RCD you will either have a problem with nuisance tripping or you have a faulty item of electrical equipment.

With nuisance tripping the standing earth leakage current should not exceed 30% of the RCD rating in mA. For a 30ma RCD this would be 10mA. In practice in an individual residential electrical installation this is a minimal problem.

SPDs should have a minimum rating of 40kA , 8/25 microsec, 275V. protected by a MCB and connected on the load side of the main switch. This will be close to the main earthing bar at the main switchboard. DIN rail mounting SPDs have replaceable plug -in modules.

Sensitive electronic equipment may have additional protection by means of surge and spike protected power boards at the socket outlets.

You are more likely to experience the effects of an indirect lightning strike than that of a direct one on an electrical installation or the effects of HV switching on the distribution network.

You should also consider where the first socket outlet for your telephone service is to be located, this should be a RJ12 or RJ45 mounted on a flush mounting plate. You should have a twin socket outlet located adjacent, about 150mm from the telephone outlet.

The location of all switches and socket outlets should be accessible at all times and not blocked by furniture or fixtures.

Thanks for the comments, but as for safety you do not see a problem with my set up for now? The SPD is what Square D recommends and yes, placed right after the main breaker. The telephone line is going approx. where you say but it will be awhile before that is in place.

No, not with safety. the SPD should be protected with a MCB and the earth from the SPD should be run to the main earth bar, minimum 4sqmm.

Can you please explain why it is unsafe? Are you then saying that if I have a RCD mainbreaker I can not have a SPD?

An RCD/RCBO is a residual current device, 30mA.

An SPD is a surge protection device to protect from spikes, surges etc exceeding 275V. they must be protected by a MCB generally 32A. DIN rail mounting units have replaceable modules and are changed when the indicator changes from green to red.

SPDs are connected on the load side of the main switch.

They are two completely different devices.

The RCDs are for safety. You are using the RCBO as a main switch in this instance.

Edited May 11, 2010 by david96

[david96]

With RCDs unwarranted or nuisance tripping is just the device doing its job, and you may have this problem if one has excessive standing leakage currents. This is not a fault and the problem is resolved by installing 2 or more RCDs. The standing leakage current is reduced on each circuit.

Electronic equipment, surge protected power boards, equipment with capacitors connected to earth for EMC

etc have higher values of standing leakage current. The problem is minimal in the average residential electrical installation.

[david96]

One very good reason for NOT using a RCBO (in this case 63A/30ma) as a main switch is if you have an earth fault on one circuit you will lose all power to your installation, lights, power etc.

[eraymos]

One very good reason for NOT using a RCBO (in this case 63A/30ma) as a main switch is if you have an earth fault on one circuit you will lose all power to your installation, lights, power etc.

That i a good reason, but the only saftey problem I see with that is if I trip in the dark going to reset the switch.

Schneider electrics Square D catalogue shows two set ups with a SPD.

1) MCB mainbreaker, SPD and then MCB and RCBO breakers

2) RCD mainbreakerm SPD and only MCBs.

Everything properly grounded.

If I am having problems , can I not shut down all breakers and turn them on one by one to find out where the problem is?

Is it then possible to switch out the breaker or el.appliance that is giving me the problem?

[david96]

One very good reason for NOT using a RCBO (in this case 63A/30ma) as a main switch is if you have an earth fault on one circuit you will lose all power to your installation, lights, power etc.

That i a good reason, but the only saftey problem I see with that is if I trip in the dark going to reset the switch.

Schneider electrics Square D catalogue shows two set ups with a SPD.

1) MCB mainbreaker, SPD and then MCB and RCBO breakers

2) RCD mainbreakerm SPD and only MCBs.

Everything properly grounded.

If I am having problems , can I not shut down all breakers and turn them on one by one to find out where the problem is?

Is it then possible to switch out the breaker or el.appliance that is giving me the problem?

This is the lowest cost option, the one you have decided on and it will give you the level of protection that you require.

[david96]

Some may be confused with the definitions of some electrical terms. Here are some.

Main switchboard (MSB). The switchboard that controls the electrical installation, the consumers mains terminate at a main switch.

Main switch. The switch controlling the electrical installation at the main switchboard. The main switch may be a MCB.

Sub board / distribution switchboard (DSB). A switchboard which controls part of an electrical installation, it is supplied by sub mains from another switch board, generally the main switchboard.

Consumers unit (CU) is a UK term for sub board.

Loadcentre is another term for a distribution switchboard.

Final subcircuit. A circuit that has a protective device and that does not supply a sub board

eg lighting and power circuits are final subcircuits.

RCD is any residual current device. (The generic term is "Safety Switch").

RCCD is a residual current circuit breaker. operates only on residual current. (earth leakage)

RCBO is a device that combines the functions of an MCB and a RCD. (Residual Current Breaker Overload) a 63A MCB with a 30mA RCD is an RCBO.

Protective device, can be a Fuse, MCB, RCCD or RCBO. any device that provides electrical protection, eg SPD is a surge protection device.

[Crossy]

One very good reason for NOT using a RCBO (in this case 63A/30ma) as a main switch is if you have an earth fault on one circuit you will lose all power to your installation, lights, power etc.

A good reason for using a split load CU or, if you still want RCD protection of all your circuits, a UK "17th Edition" board with 2 RCDs.

Personally, I'd go with the split load board, keeping ceiling lights, aircons and the freezer on the non-RCD side.

[eraymos]

One very good reason for NOT using a RCBO (in this case 63A/30ma) as a main switch is if you have an earth fault on one circuit you will lose all power to your installation, lights, power etc.

A good reason for using a split load CU or, if you still want RCD protection of all your circuits, a UK "17th Edition" board with 2 RCDs.

Personally, I'd go with the split load board, keeping ceiling lights, aircons and the freezer on the non-RCD side.

The only place that I have found 17th editions are in England with 100A mains. I looked into this with my distributor in Thailand to see if I could get it with a 63A main. They acted like they did not know what I was talking about. Sent them pictures too! They then came up with the set up that I'm talking about buying now. As I've said before I am in Norway for now, so everything goes via telephone and e-mails. Not the easiest way to do things.

My wife is my translator and she tries her best to explain things to our distributor and electrician, but I don't know how much any of them understand. I have thought about making a split board like you show on your web page, I will have to wait until i get to Thailand and see how much the electrician understands and see if we can split the neutral bar and change things around. That is also why I have said before that if I have problems with things, I can upgrade the CU. Does this make sense???

[david96]

Ref to post #136.

You can purchase a 24 module polycarbonate surface mounted enclosure with DIN rail with neutral and earth bars.

You then install 2 or more 4 pole RCCDs and protect them on the line side with MCBs. 2 RCCDs will cover 6 final sub circuits.

Alternatively you can install 1 x 2 pole RCBO for each circuit that has socket outlets connected. Eg. 6 RCBOs

You still use the 63A MCB as the main switch.

Edited May 13, 2010 by david96

[elkangorito]

Sorry Eraymos but I no longer have the initial MD calculation, which I did for you. I know that it's a pain but could you please tell me again exactly how many power outlets (single & double), motors (above & below 2.2kW), lights (assuming that each fitting can only accommodate a maximum 60W lamp) & water heaters (size in Watts) please.

Please don't forget any cooking appliances (not plug-in) & air conditioners (please give size in electrical Watts).

I will start from scratch & will proceed from there. It won't take too long.

Edited June 11, 2010 by elkangorito

[eraymos]

Sorry Eraymos but I no longer have the initial MD calculation, which I did for you. I know that it's a pain but could you please tell me again exactly how many power outlets (single & double), motors (above & below 2.2kW), lights (assuming that each fitting can only accommodate a maximum 60W lamp) & water heaters (size in Watts) please.

Please don't forget any cooking appliances (not plug-in) & air conditioners (please give size in electrical Watts).

I will start from scratch & will proceed from there. It won't take too long.

Elkangorito,

This was you original MD calculation

Your Maximum Demand is about 64 amps without adding 20% for future usage. If you add this percentage, it will be about 77 amps. Essentially, this is normal for most western style homes of your chosen size.

As per my suggestions & moving from left to right, top to bottom of your drawing (not more than 2 x DGPO's in each bedroom):

Kitchen - 2 x DGPO. 1 x SGPO (range hood plus exhaust fan). 1 x combination light/fan. 1 x oven. 1 x cooktop.

Bathroom - 2 x lights. 1 x exhaust fan. 1 x SGPO.

Laundry - 1 x hot water heater. 1 x DGPO. 1 x light.

Master bedroom - 2 x DGPO. 1 x combination light/fan.

Bathroom - 1 x light. 1 x exhaust fan. 1 x SGPO.

Bedroom - 2 x DGPO. 1 x light.

Carport - 2 x DGPO. 1 x light.

Living room - 4 x DGPO. 6 x lights.

Hallway - 2 x SGPO. 1 x light.

Sunroom - 2 x DGPO. 1 x light.

Foyer - 1 x DGPO. 1 x light.

Bedroom - 2 x DGPO. 1 x light.

Bedroom - 2 x DGPO. 1 x light.

Outdoor - 2 x DGPO. 6 x lights.

Changes in blue

Kitchen - 4 x DGPO. 1 x SGPO (range hood / exhaust fan). 1 x combination light/fan. 1 x oven 3.24kw. 1 x cooktop 3.2kw.

Bathroom - 2 x lights. 1 x exhaust fan. 1 x SGPO/GFI.

Laundry - 1 x hot water heater 2500kW. 1 x DGPO/GFI. 1 x light.

Master bedroom - 3 x DGPO. 1 x combination light/fan.

Bathroom - 1 x light. 1 x exhaust fan. 1 x SGPO/GFI.

Bedroom -3 x DGPO. 1 x light.

Carport - 2 x DGPO. 1 x light.

Living room - 4 x DGPO. 6 x lights.

Hallway - 2 x SGPO. 1 x light.

Sunroom - 2 x DGPO. 1 x light. (fan)

Foyer - 1 x DGPO. 1 x light.

Bedroom -3x DGPO. 1 x light.

Bedroom - 3 x DGPO. 1 x light.

Outdoor - 2 x DGPO. 1xSGPO (pump). 6 x lights. 1x SGPO (pump)

Air conditioner - 1 x @ less than 10 amps

All lights max 60W

water pressure pump a "plug-in" unit that will be plugged into an outdoor outlet

GFI- I have not seen that Clipsal has this in Thailand. Haco Thailand has a 16A 250v 3 pin euro-american socket module w/ residual current protection 30mA

TO ALL OTHER TV READERS & MEMBERS:

I appreciate your comments BUT please let Elkangorito do the job I am asking him to do. Thanks!

Hope that this is all the info you need for now.

Thanks again

[elkangorito]

The Maximum Demand calc is in a spreadsheet at the bottom of the page. It is 56amps WITHOUT the 20% allowance of future load.

Kitchen - 4 x DGPO. 1 x SGPO (range hood / exhaust fan). 1 x combination light/fan. 1 x oven 3.24kw. 1 x cooktop 3.2kw.

Bathroom1 (Bt1) - 2 x lights. 1 x exhaust fan. 1 x SGPO/GFI.

Laundry - 1 x storage hot water heater 2500kW. 1 x DGPO/GFI. 1 x light.

Master bedroom (MB) - 3 x DGPO. 1 x combination light/fan.

Bathroom2 (Bt2) - 1 x light. 1 x exhaust fan. 1 x SGPO/GFI.

Bedroom1 (Br1) -3 x DGPO. 1 x light.

Carport - 2 x DGPO. 1 x light.

Living room - 4 x DGPO. 6 x lights.

Hallway - 2 x SGPO. 1 x light.

Sunroom - 2 x DGPO. 1 x light. (fan)

Foyer - 1 x DGPO. 1 x light.

Bedroom2 (Br2) -3 x DGPO. 1 x light.

Bedroom3 (Br3) - 3 x DGPO. 1 x light.

Outdoor - 2 x DGPO. 1xSGPO (pump). 6 x lights.

Air conditioner - 1 x @ less than 10 amps

All lights max 60W

water pressure pump a "plug-in" unit that will be plugged into an outdoor outlet.

Circuit allocation based on above. All equipment used is 'Square D'.

Power outlets (Cable size - 2.5mm squared copper).

Kitchen ('high load' area).

a] 1 x 20amp RCBO 30mA (2 x DGPO's).

b] 1 x 20amp RCBO 30mA (2 x DGPO's plus 1 x SGPO).

c] 1 x 20amp MCB (oven).

d] 1 x 20amp MCB (cooktop).

e] 1 x 20amp MCB (Refrigerator).

The refrigerator can be placed on a seperate "unprotected" circuit if necessary (not RCBO protected) but will need a dedicated GPO. I will incorporate this in the DB layout diagram. It will be protected by a 20amp MCB & the cable size must be 2.5mm squared copper.

Other power outlets (Cable size - 2.5mm squared copper).

a] 1 x 20amp RCBO 30mA (MB & Br1).

b] 1 x 20amp RCBO 30mA (Br2 & Br3).

c] 1 x 20amp RCBO 30mA (Living room).

d] 1 x 20amp RCBO 30mA (Outdoor).

e] 1 x 20amp RCBO 30mA (Laundry, Carport, Hallway, Sunroom & Foyer).

f] 1 x 20amp RCBO 10mA (Bt1 & Bt2).

g] 1 x 20amp RCBO 30mA (water heater).

h] 1 x 20amp MCB (Air conditioner).

Lighting (Cable size - 1.5mm squared copper).

a] 1 x 16amp RCBO (Outdoor).

b] 1 x 16amp RCBO (Bt1, Bt2, Laundry, MB, Br1, Carport, Sunroom, Br2 & Br3).

c] 1 x 16amp MCB (Kitchen, Living room, Hallway & Foyer). Please note that this circuit is NOT protected by an RCBO.

You will need a DB which has a minimum of 18 pole spaces (this includes the 2 pole Main Switch). It is, however, advisable to have some spare pole spaces. Also, if single pole RCBO's are used as I have selected, a seperate neutral bar will need to be installed. This extra neutral bar is for the 'protected' circuits. This can be avoided by using double pole RCBO's but they cost significantly more as well as taking up more pole spaces, which usually means that a bigger DB is required.

My DB recommendations are as follows & DOES NOT allow for a 20% future expansion of load:

DB - QO3100L24G/SN - list price is 6500 Baht.

This unit has 24 pole spaces & is metal. There should be enough space inside to accommodate a seperate 'protected' neutral bar. Also, I believe that this unit has 3 phase busbar. I'm not sure if it is available in single phase busbar. You need to contact Square D Thailand about this. If it is only available in 3 phase, the busbars will need to be joined for a single phase supply, which is easily done.

Equipment used:

Main Switch (not an RCBO) - 63amp 10kA 2 pole - QO263VSC10T - list price 1220 Baht.

20amp 30mA RCBO 6kA - QO120VS6RCB030 - list price 2200 Baht each.

16amp 30mA RCBO 6kA - QO116VS6RCB030 - list price 2200 Baht each.

20amp 10mA RCBO 6kA - QO120VS6RCB010 - list price 2200 Baht each.

20amp MCB 6kA - QO120VSC6T - list price 230 Baht each.

Other notes:

a] The list prices used are based on the 'Square D' 2008 catalog. These prices may have increased slightly.

b] I have assumed that your supply is IT, as is virtually every supply in my local area. This may change at some time in the future.

c] If you want to allow for an extra 20% future load, the size of the Main Switch will change from 63amp to 70amp.

d] I have chosen a 2 pole Main Switch as I assume that your supply is IT. If the supply is not IT (if it is TT or TN), this switch must be changed to single pole.

e] Consult your energy authority (PEA) with regard to your Maximum Demand & also with regard to type of supply (IT, TT or TN).

f] I have chosen 10mA RCBO's for the bathrooms as these areas are 'wet areas' (extra safety required).

The only thing outstanding is the size of your Consumer Mains. This requires the following info in order to calculate properly:

a] Will they be UG (underground)?

b] will they be 'aerial' (above ground & on poles)?

c] what is the distance from the 'point of connection' to your DB? The 'point of connection' is where the PEA connects your Consumer Mains to the power grid.

DB layout rev 0.pdf

Max Demand rev 0.xls

Edited June 13, 2010 by elkangorito

[eraymos]

Thanks Elkangorito,

I knew I could count on you.

The distance from point of connection to the DB is 60-70 meters, and above ground.

The company I'm buying from in Bangkok is going to give me 40% off list price.

Thanks again!

[eraymos]

Was looking in my SQD 2009 catalog, QO3-CON1PH single phase connector cost only 450 baht.

The load center is 6500, all other prices are the same as you say.

That comes out to 31,220 baht, minus 40% is then 18,752 baht.

That don't sound to bad!

Why 6kA and not 10kA breakers?

Thanks again!!!

[powderpuff]

So are you going with a 100 amp main & 2 x 63 amp breaker boxes? Not sure they sell 6 amp breakers. 10 is what I use.

[eraymos]

So are you going with a 100 amp main & 2 x 63 amp breaker boxes? Not sure they sell 6 amp breakers. 10 is what I use.

No, I think you misunderstand.

1 x 63 amp main.

Where I wrote about 6kA and 10kA, it has to do with the short circuit rating of the breaker.

[elkangorito]

Why 6kA and not 10kA breakers?

The catalog indicates that 'cascading' may be used with these CB's (IEC 60947-2), although cascading charts are not shown in the catalog. This means that the downstream 6kA CB's will be able to safely open on a fault that is potentially larger than 6kA.

Don't forget that the entire installation must be properly earthed. Crossy's website goes into detail.

BTW, here are some pics of bad earth stakes & connections. Take note that in pic number 2, the bare cable is between 2 nuts of dissimilar metals without the use of flat or spring washers. A more correct way to do this connection would be to use a crimped 'ring' lug on the earth cable, which would then be placed between flat washers. A spring washer would then be placed on the outer flat washer & the nut applied.

It is, however, always best to use a proper earth cable clamp, which is designed for this application.

This connection should then be painted with acrylic paint. The whole connection & cable must be protected from any kind of damage.

Edited June 14, 2010 by elkangorito

[eraymos]

Why 6kA and not 10kA breakers?

The catalog indicates that 'cascading' may be used with these CB's (IEC 60947-2), although cascading charts are not shown in the catalog. This means that the downstream 6kA CB's will be able to safely open on a fault that is potentially larger than 6kA.

Don't forget that the entire installation must be properly earthed. Crossy's website goes into detail.

BTW, here are some pics of bad earth stakes & connections. Take note that in pic number 2, the bare cable is between 2 nuts of dissimilar metals without the use of flat or spring washers. A more correct way to do this connection would be to use a crimped 'ring' lug on the earth cable, which would then be placed between flat washers. A spring washer would then be placed on the outer flat washer & the nut applied.

It is, however, always best to use a proper earth cable clamp, which is designed for this application.

This connection should then be painted with acrylic paint. The whole connection & cable must be protected from any kind of damage.

Thanks,

I have seen Crossy's website on earthing and various other sites on grounding.

I don't see any reason to skimp on grounding equipment. Why put all that money in for a good electrical system and then screw it up by jerking around with such an important saftey device.

[elkangorito]

If I get the energy, I'll work out the size of your consumer mains cable today.

Of course, once your project is at pratical completion, certain tests MUST be done prior to energisation. There is only one member I know who was able to have the appropriate tests done on his system...his nick is stgrhe. I advise to speak to him about this.

As a minimum requirement, these tests must be carried out:

a] Insulation Resistance.

b] Active/Neutral polarity.

c] Earth Fault Loop Impedance. (could be interesting on an IT system).

d] Earth continuity throughout the entire installation.

e] Correct supply voltage (220-230v).

f] A visual inspection, particularly looking for exposed 'active' parts/conductors & correct wiring of equipment.

g] Correct operation of RCBO's (can be tested after energisation).

Is the construction of the house complete? If not, now would be a good time to look at equipotential bonding. If construction is complete, it may be too late to do this.

Eraymos, what you may like to do in the meantime is to contact the PEA & verify what kind of earthing system you will be connected to. They should be able to tell you whether it is IT, TT or a TN system. This information is very important. At the same time, tell them your Maximum Demand.

Edited June 14, 2010 by elkangorito

[eraymos]

Is the construction of the house complete? If not, now would be a good time to look at equipotential bonding. If construction is complete, it may be too late to do this.

Eraymos, what you may like to do in the meantime is to contact the PEA & verify what kind of earthing system you will be connected to. They should be able to tell you whether it is IT, TT or a TN system. This information is very important. At the same time, tell them your Maximum Demand.

Equipotenial bonding? That has to do with a type of grounding of metal pipes coming out of walls and such?

I am still in Norway for now and the house is far from finished.

All the metal pipes in the bathrooms and laundry room are still exposed, not the kitchen.

The H/W tank is in the laundry room where all metal pipes originate.

If this is what you are talking about, then I don't think it's to late.

Now the question is how is equipotenial bonding done?

As far as the PEA, as said I am in Norway. The wife is going to call the house builder and or the electrician and have them call the PEA.

I understand what you are talking about, now let's hope that all parts involved understand too!!!

Edited June 14, 2010 by eraymos

[elkangorito]

I've finished the calculation for 35mm squared Aluminium aerial cables.

As you have indicated, you have a single phase installation & the Consumer Mains will be run from the 'Point Of Connection' to your house DB. They will be run as aerial cables, on poles. I have allowed an 80m length & a max voltage drop of 5.5v.

If you allow the PEA to do this, they will most likely use 35mm squared Aluminium cables in black PVC. If they use this size & type of cable, you are 'home & hosed' (no problems). If another type &/or size cable is used, I can't guarantee that things will be ok, although they may be.

If you choose to do this yourself, I will need to advise you of the type of cable to be used & you will need to get prices from electrical contractors to carry out this work.

With regard to 'equipotential bonding', any concrete rebar used in the wet areas will definitely need to be connected. This can be done by an electrician attaching an insulated copper conductor (green or green/yellow) to the rebar with an appropriate clamp. THESE CONNECTIONS ARE NOT TO BE SOLDERED. This cable (along with any other equi-bonding cables) shall then go to your DB. Ideally, the DB would have a dedicated earth bar for equipotential bonding but these cables can go to the existing earth bar. It's a good idea to lable these cables as 'equi-bonding' cables.

All metal water pipes should be connected to the equi-bonding system by an appropriate clamp (not soldered) & the cabling is the same as above.

Minimum cable size - 2.5mm squared copper.

[eraymos]

I've finished the calculation for 35mm squared Aluminium aerial cables.

As you have indicated, you have a single phase installation & the Consumer Mains will be run from the 'Point Of Connection' to your house DB. They will be run as aerial cables, on poles. I have allowed an 80m length & a max voltage drop of 5.5v.

If you allow the PEA to do this, they will most likely use 35mm squared Aluminium cables in black PVC. If they use this size & type of cable, you are 'home & hosed' (no problems). If another type &/or size cable is used, I can't guarantee that things will be ok, although they may be.

If you choose to do this yourself, I will need to advise you of the type of cable to be used & you will need to get prices from electrical contractors to carry out this work.

With regard to 'equipotential bonding', any concrete rebar used in the wet areas will definitely need to be connected. This can be done by an electrician attaching an insulated copper conductor (green or green/yellow) to the rebar with an appropriate clamp. THESE CONNECTIONS ARE NOT TO BE SOLDERED. This cable (along with any other equi-bonding cables) shall then go to your DB. Ideally, the DB would have a dedicated earth bar for equipotential bonding but these cables can go to the existing earth bar. It's a good idea to lable these cables as 'equi-bonding' cables.

All metal water pipes should be connected to the equi-bonding system by an appropriate clamp (not soldered) & the cabling is the same as above.

Minimum cable size - 2.5mm squared copper.

Thanks again for the time and effort you put in to help me!!

Equipotential bonding is what I thought it was. The price of cable is not that great so I'm sure that I will follow your recommendations.

The wife called the electrician today , but he could not give her an answer on what type of earthing system is in the area.

This don't sound to promising or should I say it doesn't make me feel to good about the electricians qualifications.

I'm going to have to watch him like a hawk, and double no triple check everything he does.

As soon as I get a chance I'll have my wife call PEA.

Thanks again for all your help!