Safety Precautions For A Temporary Electricity Supply

[Greenside]

We have a temporary supply by our bore hole and a klong. Although it's been raining a decent amount for the past day or so, our new hedge needs regular watering and the tanks and proper installation won't be ready for a little while yet. I'm contemplating buying the pump that will drive the irrigation system now and doing some kind of lash up to take water from the klong in case of dry spells.

What's the safest way to hook up a pump under these circumstances bearing in mind that I don't have shelter for any kind of fixed circuit breakers etc.?

[bankruatsteve]

Hmmm. Perhaps the safest way for YOU is to let the locals do whatever and then stay clear of it.

[gotlost]

Hmmm. Perhaps the safest way for YOU is to let the locals do whatever and then stay clear of it.

Sounds like you could use a gasoline pump from the klong.

[Crossy]

Submersible pump, RCD on the supply end (under cover of course). Local ground spike for the pump (or 3 core cable) if it's not double insulated. Waterproof connectors if the cable is not one piece.

We have a little (2") gas powered pump, cost about 4500 Baht a few years back, perfect for the watering jobs far from the power supply, shifts a lot of water and is impervious to rain and being watered by Wifey.

[Greenside]

Submersible pump, RCD on the supply end (under cover of course). Local ground spike for the pump (or 3 core cable) if it's not double insulated. Waterproof connectors if the cable is not one piece.

We have a little (2") gas powered pump, cost about 4500 Baht a few years back, perfect for the watering jobs far from the power supply, shifts a lot of water and is impervious to rain and being watered by Wifey.

I was thinking about one of those which are 5200 baht at Global House right now but this situation should only last a few weeks so, although it's not a lot of money a gas pump isn't going to see much use after that unless we have protracted power outages. Thanks for the info.

[gotlost]

Submersible pump, RCD on the supply end (under cover of course). Local ground spike for the pump (or 3 core cable) if it's not double insulated. Waterproof connectors if the cable is not one piece.

We have a little (2") gas powered pump, cost about 4500 Baht a few years back, perfect for the watering jobs far from the power supply, shifts a lot of water and is impervious to rain and being watered by Wifey.

I was thinking about one of those which are 5200 baht at Global House right now but this situation should only last a few weeks so, although it's not a lot of money a gas pump isn't going to see much use after that unless we have protracted power outages. Thanks for the info.

Agree with Crossy. Put the motor/pump on wood, ground road, three conductor cable AND cover the motor to keep rain out. Along with water proof connections and some kind of breaker. You should be ok.

[Greenside]

Things have moved on a bit so now we have a small building to use as a pump house/toolshed. We have the following installed (or about to be):

1.5 Franklin Submersible Pump in the borehole + a Franklin Control Box and an Auto Control Box

An Hitachi 400W house pump

A 2HP automatic pump for the irrigation, presumably with another control box (they seem to be reproducing by themselves here!)

In addition, there is a double power socket and a 40W fluorescent light in the hut.

We are still on the temporary supply (15/45 with two 16mm aluminium cables running 150m from the road) and have bought a consumer unit with six breakers + rcbo and installed a 1.8m ground rod. The Well Guy is soon to route the temporary supply to the CU but I have my doubts about his competency when it comes to wiring so I'd like to keep an eye on what he's doing. It's still to be a temporary supply but hopefully safer and more convenient than the present terminal mounted outside in a plastic box. My questions:

1. The two lines coming in: I assume one to be live and the other neutral which will connect to the appropriate places in the CU. How should he test to determine which is which?
2. He says it's fine to run the light and the power point on the same circuit and through the same MCB. I seem to remember that's frowned upon in the UK - is it safe?
3. Suggested ratings for the MCBs? I don't have the list in front of me but I think the unit came with 10A/10A/16A/20A/20A/32?

On a slightly different subject, I see warnings in several threads here about connecting two pin plugs "the right way round", especially when using extension leads. How can you tell which should be the neutral and which the active (I assume that's the same as live) pin on either the appliance or the socket?

Many thanks as ever.

[electau]

Instal lighting 1x36w and 10A socket outlet in 2.5sqmm twin and earth cable protected by a 20amp RCBO. (Mixed circuit)

All socket outlets must be earthed, no 2 pin outlets.

Pump circuits install with 2.5sqmm twin and earth cable protect by a 20amp RCBO.

The other option is to use one RCD and MCBs for the final subcircuits.

Any switches and outlets exposed to the weather should be weatherproof to IP56.

Installation testing should be carried before connection to supply including a polarity test, L to N, N to E and L to E.

Edited October 25, 2010 by electau

[David006]

Instal lighting 1x36w and 10A socket outlet in 2.5sqmm twin and earth cable protected by a 20amp RCBO. (Mixed circuit)

All socket outlets must be earthed, no 2 pin outlets.

Pump circuits install with 2.5sqmm twin and earth cable protect by a 20amp RCBO.

The other option is to use one RCD and MCBs for the final subcircuits.

Any switches and outlets exposed to the weather should be weatherproof to IP56.

Installation testing should be carried before connection to supply including a polarity test, L to N, N to E and L to E.

..all our pumps came with two pin plugs...easy enough to bond to ground rod though..reckon the problem of polarity of two pin plugs is insurmountable without polarity checking?? and changing the plug to three pin...but of doubtful consequence for ac motors..what do you think?

[electau]

The pumps fitted with 2 pin plug tops may be double insulated and if so they should be marked with a square within a square on the nameplate. If so you can still use the 2 pin plug top. It would be advisable to install 3 pin socket outlets.

Polarity testing refers to the incoming mains supply, along with correct circuit connections within the electrical installation.

　

[Greenside]

Our Hitachi 400W came with a two pin plug and separate earth. The cable was very small to my mind (2 x 0.75mm) and the Well Guy replaced it with a 3 x 1.00 into one of the 10A MCBs - the run is 5m, by the way. Does that sound OK?

The whole board is protected by one RCB which sits next to the main breaker (63A).

How do you do a polarity check on an appliance?

Edited October 26, 2010 by Greenside

[Crossy]

I wonder if he's done anything with that green wire in the 3 x 1mm

Modern appliances are polarity insensitive so a L-N reversal is not so much of an issue as it was in the days of live-chassis TVs etc.

[Greenside]

I wonder if he's done anything with that green wire in the 3 x 1mm

Modern appliances are polarity insensitive so a L-N reversal is not so much of an issue as it was in the days of live-chassis TVs etc.

The green wire has gone to earth in the CU and replaced the separate ground from the pump. I assume from your lack of comment that 1mm is sufficient for the pump, given the original cable size?

Edited October 26, 2010 by Greenside

[Crossy]

I assume from your lack of comment that 1mm is sufficient for the pump, given the original cable size?

1mm² is good for at least 10A (2000 Watts plus) The 0.75 as originally fitted would have been fine if it was 3-core.

[electau]

Correct circuit connections.

3 pin socket outlets. Earth, Line, Neutral viewed looking at the front of the socket outlet in a clockwise direction. Socket outlets should be marked.

3 pin plug tops. Earth,Neutral, Line viewed looking at the pins (not the terminals) of the plug top in a clockwise direction. If looking at the terminals they should be marked and will be the same as the socket outlet.

Exception is the Schuko plug top which should be used only with a matching Schuko socket outlet. Again the terminals will be marked.

Schuko plug tops are reversable if used in the standard TIS outlet. Earthing will not be achieved.

3 pin moulded plug tops are the norm now on most portable electrical appliances.

2 pin moulded plug tops on DI or SELV equipment.

No earthing or poor earthing creates a potential electrical hazard. All socket outlets should be protected by an RCD.

Polarity testing. L to E supply voltage. N to E 0 volts. L to N supply voltage. Switches must operate in the Line (Active) conductor.

[Crossy]

electau. The Thai outlets have L on the Left if ground is at the top. So clockwise from ground it's E N L looking at the socket.

Like this :-

this TIS plug has the pins marked :-

Schuko to TIS adaptors that provide ground continuity are available, they look like this :-

Schuko plugtops are reversible even if installed in a matching outlet (except in Belgium and France which have a polarising/ground pin in the outlet).

[electau]

The 3 pin plug tops and socket outlets one was refering to were to the IEC, BS and AS3112 standards. The TIS socket outlets are a compromise between the 2 pin round Europlug and the parallel blade NEMA and JP standards. They are polarised the neutral pin socket is wider so as to accept the polarised 2 pin parallel blade plug top. The L and N positions are reversed.

I should have been clearer in the explanation.

The socket outlet used in China (PRC) is the same pattern as the AS3112 type but does not comply with AS3112. The earth pin is to the top as in the BS outlet.

And all socket types may be found in Thailand, but the TIS type is the most common and is the defacto standard.

The advantage of the AS and the BS types is that they are not directly interchangeable and the NEMA and JP style plugs do not fit either of them.

Thailand needs to mandate the use of the 3 pin round plug top and the 2 pin Euro plug top as a common standard, and it appears to be trying to do this.

Thailand mixes two standards for some reason the IEC and the NEMA/JP.

Yes, earthing will not be achieved unless an adaptor is used

with TIS outlets, no adaptor no earthing. And the socket outlet should be earthed

Edited October 27, 2010 by electau