3 phase single phase. help needed crossy

[carlyai]

[...]

Thai electrician (great electrician), got everything working but he didn't install the 3 10kva avrs or the input from the single phase desiel gen thru the changeover switch to power 1 phase with essential lights etc when the power failed.

[...]

I just noticed that Crossy isn't suggesting you put an RCD on the 1-phase Diesel Generator output.

While this is probably fine for "Essential Lighting", I would suggest you mark the inside of the Panel Lid and indicate which phase line you are designating/restricting to "Essential Connections Only", and list what those "Safe and Essential" connection types might be (written in both Thai and English).

While "I" might be willing add an isolated power socket or two on that restricted phase, I would hope you'd add an additional RCD on the line from the Generaror before giving-in and adding an "Essential" kitchen appliance (or any circuit where human contact to current might be a real potential).

I don't know how long your power outages typically are. So, besides lights, what other "Essentials" might you have?

Overhead Lights

Water Pump

Power Socket for recharging phone batteries

Power Socket for a Fan or two

Deep Freezer

Wine Cooler Cabinet

Kitchen Refrigerator

Kitchen Hotplate *

Microwave or Turbo Oven *

(*Most Thais easily convert to Charcoal Fire for heating and cooking needs)

Thanks for the reply.

Initially I had the phases balanced and one phase with essential services, lights, power, freezer, tv, move dish plus an air con to load the deisel to stop bore glazing.

I am not going to worry about the deisel gen set at the moment until I get the safety cut and avrs sorted.

[carlyai]

Don't do medical here, 'lectrics only

Do it something like this:-

3-phase transfer.jpg

Before we go hooking anything up it is essential that we know how the AVRs are wired internally, specifically the connection which is straight through input-output, as noted earlier this should be the neutral.

Note that is is vital that your transfer switch opens all three phases and the neutral even if only one phase has generator supply. Leaving two dead phases connected whilst running on generator will cause interesting (potentially explosive) effects when the power returns.

Thanks for the wiring diagram.

I'm a bit embarrased to ask any more questions, but, where do you earth the nuetral in this set up?

The AVR's I bought are LiOA SH-10000, 10 KVA. Will send the pic when I can.

[Crossy]

The N-E link would be in the Safe-T-Cut, it's shown in the instructions for connecting it up.

There should be no other such links downstream, if you have them the Safe-T-Cut may trip randomly (with load) or not stay 'on' at all.

You may need to link N-E of the genset, it's worth talking to the manufacturer, small units probably won't have the facility.

[RichCor]

Thanks for the wiring diagram.

I'm a bit embarrased to ask any more questions, but, where do you earth the nuetral in this set up?

The AVR's I bought are LiOA SH-10000, 10 KVA. Will send the pic when I can.

The N-E link would be in the Safe-T-Cut, it's shown in the instructions for connecting it up.

There should be no other such links downstream, if you have them the Safe-T-Cut may trip randomly (with load) or not stay 'on' at all.

You may need to link N-E of the genset, it's worth talking to the manufacturer, small units probably won't have the facility.

carlyai,

Just want to make sure, your 3-Phase Transfer Switch also switching Neutral (full 4-wire switching)?

Depending on the generator design, many will have N-G tied at the frame of the generator. If the Transfer Switch doesn't switch Neutral you'll have issues with the RCDs and safe operation of the system.

Your question on Neutral-Earth Tie is a critical one that you'll want to follow up.

I was looking for sample diagram that incorporated Mains, Generator, RCDs, Transfer Switch and Grounding -- as it's very important to know Where to Establish the Main Ground, Where to Bond N-G, Where to Place the RCDs).

Maybe Crossy can modify his diagram.

[Crossy]

Maybe Crossy can modify his diagram.

Will do, the previous one was a quick and dirty to get the idea down on paper.

Indeed it is vital that the transfer switch breaks all 4 lines, preferably with the neutral being break last - make first.

[carlyai]

Thanks again for the replys.

I did order a 4 pole automatic/manual transfer switch from China and will see if I can find a wiring diagram.It can be switched to manual or auto.

I seem to remember that the diesel op's are floating, or can be configured to what u want. Will look further.

Let me get back to the house and draw up a wiring diagram from the block diagram Crossy supplied and post it to see what you all think.

[carlyai]

Thanks for the wiring diagram.

I'm a bit embarrased to ask any more questions, but, where do you earth the nuetral in this set up?

The AVR's I bought are LiOA SH-10000, 10 KVA. Will send the pic when I can.

The N-E link would be in the Safe-T-Cut, it's shown in the instructions for connecting it up.

There should be no other such links downstream, if you have them the Safe-T-Cut may trip randomly (with load) or not stay 'on' at all.

You may need to link N-E of the genset, it's worth talking to the manufacturer, small units probably won't have the facility.

carlyai,

Just want to make sure, your 3-Phase Transfer Switch also switching Neutral (full 4-wire switching)?

Depending on the generator design, many will have N-G tied at the frame of the generator. If the Transfer Switch doesn't switch Neutral you'll have issues with the RCDs and safe operation of the system.

Your question on Neutral-Earth Tie is a critical one that you'll want to follow up.

I was looking for sample diagram that incorporated Mains, Generator, RCDs, Transfer Switch and Grounding -- as it's very important to know Where to Establish the Main Ground, Where to Bond N-G, Where to Place the RCDs).

Maybe Crossy can modify his diagram.

The transfer switch is a type HYCQ5M-63A 4P

I have attached the specs and a wiring diagram, but it still doesn't show if the switch switches neutrals or not.

Maybe I have to get in touch with the manufacturer and get a better wiring diagram?

383e4b413d61437e82c05456afb0dcfb.pdf

[bankruatsteve]

Looks to me like page 6 explicitly shows switching 4 poles. (?)

[Crossy]

Looks to me like page 6 explicitly shows switching 4 poles. (?)

The "4P" designation indicates it is 4 pole

Should have 4 big terminals on each corner (16 in total) plus the green aux connector.

EDIT The AVRs are servo-control variac transformers, should be easy to connect up

[carlyai]

Looks to me like page 6 explicitly shows switching 4 poles. (?)

Because the diagram didn't show the relay make break contacts i wasn't 100% sure.

[carlyai]

Looks to me like page 6 explicitly shows switching 4 poles. (?)

The "4P" designation indicates it is 4 pole

Should have 4 big terminals on each corner (16 in total) plus the green aux connector.

EDIT The AVRs are servo-control variac transformers, should be easy to connect up

All sounding a bit better now. Thanks.

Will come up with the wiring diagram and get you to pass judgement before I do anything.

[RichCor]

HYCQ5M Technical Specifications:

• The switch mechanical life(N-R-N circulation) is 5000 times

I probably wouldn't be operating this in Automatic Restore Mode then.

The way PEA operate around here; they restore power, cut it, restore it, cut it, restore it, wait 5 minuites (roughly), cut it for 15 minutes (roughly), then restore it. Oddest method I have ever experienced. I have NO IDEA what they could be doing during this process/procedure. But if I had a Transfer Switch, it would be cycled 3 to 5 times (depending on the cut time and restore time-out interval.

In one of my many lives I was the main engineer for a group of AM/FM radio stations. I would always wait one hour after stable power was restored before switching back to mains. Transfer Switches are a pain to have to replace.

[RichCor]

Looks to me like page 6 explicitly shows switching 4 poles. (?)

The "4P" designation indicates it is 4 pole

Should have 4 big terminals on each corner (16 in total) plus the green aux connector.

EDIT The AVRs are servo-control variac transformers, should be easy to connect up

All sounding a bit better now. Thanks.

Will come up with the wiring diagram and get you to pass judgement before I do anything.

Document doesn't say if the Neutral Pole is Break Last, Make First.

[IMHO]

The way PEA operate around here; they restore power, cut it, restore it, cut it, restore it, wait 5 minuites (roughly), cut it for 15 minutes (roughly), then restore it. Oddest method I have ever experienced. I have NO IDEA what they could be doing during this process/procedure.

1) reset the switch. oops off again

2) reset the switch, oops off again

3) wiggle the wires & reset the switch, bugger only lasted 5 mins

4) fix the actual fault, now it works

[carlyai]

HYCQ5M Technical Specifications:

• The switch mechanical life(N-R-N circulation) is 5000 times

I probably wouldn't be operating this in Automatic Restore Mode then.

The way PEA operate around here; they restore power, cut it, restore it, cut it, restore it, wait 5 minuites (roughly), cut it for 15 minutes (roughly), then restore it. Oddest method I have ever experienced. I have NO IDEA what they could be doing during this process/procedure. But if I had a Transfer Switch, it would be cycled 3 to 5 times (depending on the cut time and restore time-out interval.

In one of my many lives I was the main engineer for a group of AM/FM radio stations. I would always wait one hour after stable power was restored before switching back to mains. Transfer Switches are a pain to have to replace.

They used to do a similar thing in Groote Elandt (Aus) because they had lots of bats.

Bats would short out the line, trip the switches, so the sparkys would restore power to try and blow the bat off a few times.

May be it's because of a possum problems here, as I have noticed there seem to be possum guards leading to all the overhead HV lines now.

Seems like my life before was in a similar enployment to you, but me with the old PMG dept in radio/tv/microwave.

In the Vietnam era (during a commissioning job), we used to blast 5 X 250 KW HF power transmitters at the lovely listeners over there.

It was amazing to see the corona of about 2 m radiating from one of the dipoles onto a disintegrated fly.

[Crossy]

Document doesn't say if the Neutral Pole is Break Last, Make First.

As this is a professionally designed unit I would assume (dangerous I know) that it does work like that.

It should switch:-

Normal

Off (delay)

Reserve

Off (delay)

Normal

[carlyai]

At the house now and have thought of another solution.

The 2 three phase multi-point water heaters are: stiebel eltron DHF13C types.

The 'operating and installation instructions' are for a range of heaters: DHF13C, DHF15C, DHF18C, DHF21C, DHF24C, and the DHF12C1 and DHF13C3.

The DHF12C1 is a single phase 220/230V unit, and the DHF13C3 is a 3 phase 230V unit.

The mechanical dimensions seem to be the same for all units, and most of the specs are the same except for the 3 phase voltage and single phase voltage. Also the flow rates and different stage power outputs.

The specs for the DHF13C (400 V) unit and the DHF12C1 (220 V) units are nearly the same.

Maybe there is a plug in module, with some wiring changes that differentiates a 400 V unit from a 220 V or 230 V three phase unit?

I think my best plan is to change the 3 phase water heaters for single phase water heaters, or change the DHF13C for a DHF12C1.

This may not be too difficult if I can swap over an internal module in the unit.

I will get in touch with the German supplier and see what they say.

As you can guess, when you're not there for the fitting out of the house, the heaters have been installed in 'hard to get at places'.

[RichCor]

Has Crossy sent you an updated sample power schematic, or do you see any need to propose changes (now that you are onsite)?

[carlyai]

Has Crossy sent you an updated sample power schematic, or do you see any need to propose changes (now that you are onsite)?

The way we left it was that I was going to draw up a wiring diagram and post it for comment.

I will still do that, and have been communicating with the makers of the hot water systems to get their technical reading of the heater wiring diagram. There were a few things I didn't understand about the relay symbols they used.

I contacted the states and they put me onto the technical dept in Germany. Very helpful people.

I have drawn out the 3 phase safety-cut and have the wiring for the heaters, so I will put it all together and post it.

In the mean time, what do you think of trying to get a replacement module for the 3 phase unit to make it into a single phase unit?

Or better still, what do you think of just having single phase multi-point water heaters?

If I keep the three phase heaters and wire it like Crossy's block diagram, I'm going to have to knock down some parts of walls to run more cables, as I want the AVR's outside the house to minimise heat dissipation in the house.

Maybe that's not a problem?

At the moment the mains power runs underground to the house transfer switch. From there it runs through a raceway and cavity bricks to the distribution board.

[RichCor]

[...]

The DHF12C1 is a single phase 220/230V unit, and the DHF13C3 is a 3 phase 230V unit.

The mechanical dimensions seem to be the same for all units, and most of the specs are the same except for the 3 phase voltage and single phase voltage. Also the flow rates and different stage power outputs.

The specs for the DHF13C (400 V) unit and the DHF12C1 (220 V) units are nearly the same.

Maybe there is a plug in module, with some wiring changes that differentiates a 400 V unit from a 220 V or 230 V three phase unit?

I would think the whole unit would need to be replaced, as the Heating Coils in the DHF13C3 are 400v type. So, unfortunately, not just a sub-module replacement.

[carlyai]

[...]

The DHF12C1 is a single phase 220/230V unit, and the DHF13C3 is a 3 phase 230V unit.

The mechanical dimensions seem to be the same for all units, and most of the specs are the same except for the 3 phase voltage and single phase voltage. Also the flow rates and different stage power outputs.

The specs for the DHF13C (400 V) unit and the DHF12C1 (220 V) units are nearly the same.

Maybe there is a plug in module, with some wiring changes that differentiates a 400 V unit from a 220 V or 230 V three phase unit?

I would think the whole unit would need to be replaced, as the Heating Coils in the DHF13C3 are 400v type. So, unfortunately, not just a sub-module replacement.

You may well be correct, but the wiring diagram for the 3 phase 400V heater is the same as for the 230V 3 phase heater.

I am assuming:

Between the phases of a 3 phase system the voltage is 220V. So each heating coil is only using a 220V supply.

This is the same as a single phase heater.

May be the only reason they have 3 phase heaters and single phase heaters is that some people have 3 phase installations and others have single phase installations.

May be that's the reason I could not find much information comparing the advantages and disadvantages of 3 phase and single phase heaters, other than somewhere I read the water was hotter.

As I said before I am rusty with my theory (except for Kirchoff's Laws) and I might be talking garbage.

[Crossy]

Be very careful here.

Thailand is 3-phase 4-wire, 220V is phase-neutral, phase-phase is 380V.

[carlyai]

Be very careful here.

Thailand is 3-phase 4-wire, 220V is phase-neutral, phase-phase is 380V.

Yes, sorry my wrong thinking.

What do you think about changing the 3 phase instant multi-point to 1 phase instant multi-point heaters?

The only specs that are different are the two stage heating. The 3 phase has stage 1 at 6.6. KW and the single phase 8 KW, while stage 2 is 13.2 KW for 3 phase and 12 KW for single phase.

The 3 phase units were expensive, about B 8500 each. Don't know why I was talked into buying them as against the single phase heaters.

[IMHO]

Be very careful here.

Thailand is 3-phase 4-wire, 220V is phase-neutral, phase-phase is 380V.

Yes, sorry my wrong thinking.

What do you think about changing the 3 phase instant multi-point to 1 phase instant multi-point heaters?

The only specs that are different are the two stage heating. The 3 phase has stage 1 at 6.6. KW and the single phase 8 KW, while stage 2 is 13.2 KW for 3 phase and 12 KW for single phase.

The 3 phase units were expensive, about B 8500 each. Don't know why I was talked into buying them as against the single phase heaters.

How many water heaters are you talking about? A 200L solar hot water system can be installed for around 40K Baht.... and it will only need 1500w of electricity to top up the temperatures on cold, cold days.

[LindaLovelace]

Be very careful here.

Thailand is 3-phase 4-wire, 220V is phase-neutral, phase-phase is 380V.

Yes, sorry my wrong thinking.

What do you think about changing the 3 phase instant multi-point to 1 phase instant multi-point heaters?

The only specs that are different are the two stage heating. The 3 phase has stage 1 at 6.6. KW and the single phase 8 KW, while stage 2 is 13.2 KW for 3 phase and 12 KW for single phase.

The 3 phase units were expensive, about B 8500 each. Don't know why I was talked into buying them as against the single phase heaters.

How many water heaters are you talking about? A 200L solar hot water system can be installed for around 40K Baht.... and it will only need 1500w of electricity to top up the temperatures on cold, cold days.

Do you have a link to this specific system? I'm interested.

[IMHO]

Be very careful here.

Thailand is 3-phase 4-wire, 220V is phase-neutral, phase-phase is 380V.

Yes, sorry my wrong thinking.

What do you think about changing the 3 phase instant multi-point to 1 phase instant multi-point heaters?

The only specs that are different are the two stage heating. The 3 phase has stage 1 at 6.6. KW and the single phase 8 KW, while stage 2 is 13.2 KW for 3 phase and 12 KW for single phase.

The 3 phase units were expensive, about B 8500 each. Don't know why I was talked into buying them as against the single phase heaters.

How many water heaters are you talking about? A 200L solar hot water system can be installed for around 40K Baht.... and it will only need 1500w of electricity to top up the temperatures on cold, cold days.

Do you have a link to this specific system? I'm interested.

http://www.ravotek.co.th/

[carlyai]

Be very careful here.

Thailand is 3-phase 4-wire, 220V is phase-neutral, phase-phase is 380V.

Yes, sorry my wrong thinking.

What do you think about changing the 3 phase instant multi-point to 1 phase instant multi-point heaters?

The only specs that are different are the two stage heating. The 3 phase has stage 1 at 6.6. KW and the single phase 8 KW, while stage 2 is 13.2 KW for 3 phase and 12 KW for single phase.

The 3 phase units were expensive, about B 8500 each. Don't know why I was talked into buying them as against the single phase heaters.

How many water heaters are you talking about? A 200L solar hot water system can be installed for around 40K Baht.... and it will only need 1500w of electricity to top up the temperatures on cold, cold days.

I only have two multi-point hot water heaters.

One for the second bathroom and kitchen, and one for the main bathroom and laundry.

Initially I did want to go with solar, but couldn't see any suppliers who had been in the solar business in Thailand for a long time.

I ended up going for a main storage type system to supply everything, as I don't like the instant hot water systems.

When the original builder departed, the cavity walls were going up, and he still hadn't installed the hot water pipes, so to make the installation easier I went for the instant hot water systems.

Still don't like them, if you take the covers off, they look pretty dangerous and nasty to me, but we've got good, fairly instant hot water, so can't complain.

[RichCor]

[...]

When the original builder departed, the cavity walls were going up, and he still hadn't installed the hot water pipes, so to make the installation easier I went for the instant hot water systems.

Still don't like them, if you take the covers off, they look pretty dangerous and nasty to me, but we've got good, fairly instant hot water, so can't complain.

So long as they're connected directly to a 3-phase Safe-T-Cut you shouldn't have any problem.

Blenders look pretty dangerous and nasty to me, but they still make delicious margaritas (or fruit shakes).

CAUTION: Do Not attempt to operate a pretty dangerous and nasty blender while under the influence of several margaritas.

[carlyai]

[...]

When the original builder departed, the cavity walls were going up, and he still hadn't installed the hot water pipes, so to make the installation easier I went for the instant hot water systems.

Still don't like them, if you take the covers off, they look pretty dangerous and nasty to me, but we've got good, fairly instant hot water, so can't complain.

So long as they're connected directly to a 3-phase Safe-T-Cut you shouldn't have any problem.

Blenders look pretty dangerous and nasty to me, but they still make delicious margaritas (or fruit shakes).

CAUTION: Do Not attempt to operate a pretty dangerous and nasty blender while under the influence of several margaritas.

I have purchased, but still not installed the 3 phase safety-cut.

Not confident enough to do it, I'm afraid.

Just going thru the wiring as I see it, before I go to see the electrician with the new plan for the safety-cut etc.

There seem to be a couple of earth spikes. One in an electrical box about 30 m from the road side meter. This has a EZC 100 B 60A breaker with 3 poles and the incoming neutral wire is bolted together with the outgoing nuetral wire going to the house and also going down to an earth rod/spike.

We put this box in so I could take a phase of to the garage, when it gets built.

The 4 wires then go about 20 m to another electrical box that has the gen set change over switch and then run via a cable run way inside the house to the consumer box.

In the consumer box the neutrals are tied to earth and then the earth cable goes back outside to another earth spike.

I was there when this was going on, but left the electrician to it as he seemed to know his business, now I'm a little worried about all the earth spikes from what Crossy said about having only one earth downstream.

There are 29 actives and only 23 neutrals, but there are two 3 pole breakers for the two 3 phase hot water heaters, so may be that can account for not having the same number of neutrals.

I don't know anymore.

[Crossy]

OK.

No problem with multiple earth-neutral links PROVIDED they are all upstream of (before) the Safe-T-Cut (so the link in the consumer unit will need to be removed).

I would actually avoid N-E links anywhere downstream of the genset transfer switch (you need to verify that the genset is OK with N-E linked).

Your 3-phase water heaters account for the lack of two neutrals, others could be borrowed, bad practice.