earth rod & generated power

[zeroberto]

Hi all

follow up to previous thread - got a genny supplying 227v across L/N, 110v across L/E & N/E. spoke to engineer who recently rewound it, says those readings are correct given the way that its wound.

So when I come to connect a temporary electric boiler so that under floor heating can get going (mains power not in for 6 weeks or so) it goes straight to lockout. Just about to call Trianco technical but guess that the PCB isnt liking the voltage readings above.

What would happen if I sunk an earth rod & used that as earth rather than the generator supplied Earth which is one of the suggestions ive been given. Not sure it will change anything given that the N is apparently a 110v supply but willing to listen.

Don'tr know enough about generated supplies so hoping those with better knowledge can help out.

ta

ze

 

[Rockingit]

It sounds to me like the Earth is a centre-tap off the coil. An earth rod would solve this, but you'd need to compensate for the lack of a fault loop by using an RCD on the circuit.

Probably. Happy to be corrected!!

 

[zeroberto]

Follow up to this. Called Trianco technical who told me that these boilers dont like generated power as opposed to mains. Apparently the Hertz and the sine wave are all over the place with a generator, and unless it is one which can supply a "clean" (his words) 230v supply, which you can get but are very expensive, it wont work. The PCB doesnt like it. As soon as I mentioned generator he went uh huh, apparently theyve had a few calls re this.

So the builder has to get the mains in.

Zeroberto

 

[Rockingit]

Yes, I've had this many many times. A typical pop-pop builders genny isn't up to much beyond power tools. The sets we use for 'proper' mains are an entirely different breed and yes, cost a bit more!

 

[zeroberto]

Thanks rockingit, any links to a clean genny I can pass on to them?

cheers

 

[Rockingit]

depends on where in the country you are as to what rental companies will be near you. PM me some details and I'm sure I'll know someone at least in the region.

Generally speaking, the rental companies stock 10-200kVa sets as standard, they tend to be hushgens, variety of tow/trailer or forks/hi-ab loading combinations and the smaller (10-100kVa sets) have integral bunded fuel tanks good for about 200 litres. Variable trips on many, output via either busbar on lugs or ceeform (typically a 63/3).

 

[Bitslice]

I've seen a generator output via an attached constant voltage transformer (CVT)

Getting a CVT in the UK is a bind though, most appear to be on import from the USA at £300 a unit !

Alternatively for mains sensitive electronics try a sine output inverter fed from a deep cycle battery, I think you can charge that from the 12v output from some generators.

 

[MarkieSparkie]

You could run a double-conversion (on-line) uninterruptible power supply between the generator and load. The main advantage to the on-line UPS is its ability to provide an electrical firewall between the incoming utility or local generator and sensitive electronic loads. The double-conversion UPS provides a buffer from the power quality problems of the generator. It allows control of output voltage and frequency regardless of input voltage and frequency of the rough incoming supply.