110v power issues

[MarkyofftheMark]

I work on a site that has a transformer which supplies 10 commando sockets at 100v.
Recently, I have been unable to run 110v equipment, such as drills on these sockets.

I have checked the transformer which is 110v from Live to Neutral and 58v Live to Earth; which is correct. I am also getting these readings at each commando socket which doesn't work.

I have tested the same drill on another 110v circuit and it works fine. I have even compared the readings of the sockets on the different circuits and they are the same; give or take a volt or two.

So, I am totally perplexed!! Any ideas ?

 

[Marvo]

I wouldn't worry about the L-E voltage. Retest the L-N voltage with some load on one of the 110v sockets. If the voltage is significantly less than your off-load test result then disconnect it and check the continuity of the transformer windings. Maybe also use an analogue voltmeter for the tests.

 

[telectrix]

1.bad connection breaking down under load.

2. transformer overloaded and/ or too long cable runs causing volt drop under load.

 

[Guest111]

As Tel said,bad connection,check the mcb,s on the front panel it,s possible they may be faulty,dust ingress etc.Quickest solution is to ring the hire company and get them to bring a replacement.

 

[MarkyofftheMark]

Thanks for all your responses, I'll look into it. The Transformer is quite old, so may need to be replaced.

 

[stylus]

Have you checked at the transformer,or just at the secondary distribution point.Normally these transformers are centre tapped to earth L1 to E 55v. L2 to E 55v. L1 to L2. 110v.(check the tally plate) Just think about it and work methodically through the circuit.

 

[Risteard]

Just to be pedantic there is no neutral conductor on the secondary side.

I work on a site that has a transformer which supplies 10 commando sockets at 100v.
Recently, I have been unable to run 110v equipment, such as drills on these sockets.

I have checked the transformer which is 110v from Live to Neutral and 58v Live to Earth; which is correct. I am also getting these readings at each commando socket which doesn't work.

I have tested the same drill on another 110v circuit and it works fine. I have even compared the readings of the sockets on the different circuits and they are the same; give or take a volt or two.

So, I am totally perplexed!! Any ideas ?

 

[MarkyofftheMark]

Yes I've checked them. All the voltage readings and the same as another Transformer which is functional. I'll have a look at the Voltmeter under load and see what comes up.

 

[Bobster]

This is pretty basic stuff. Are you a trainee?

 

[MarkyofftheMark]

The fact that I've obtained correct readings from commando points just threw me off course slightly. My experience in fault finding on transformers is not great, so this forum has been very helpful. Thanks once again for all your feedback bar one of you, I think you know who you are.

 

[Knobhead]

The Transformer is quite old, so may need to be replaced.

Transformers don’t wear out. They may burn out.

You need to do the full range of tests on it. As RoB said, it’s basic stuff.

If you are a trainee either RoB or myself will help out. For myself I won’t do training in open forum due to others getting in the way.

 

[Geordie Spark]

Transformers don’t wear out. They may burn out.

You need to do the full range of tests on it. As RoB said, it’s basic stuff.

If you are a trainee either RoB or myself will help out. For myself I won’t do training in open forum due to others getting in the way.

Hellooooooooooo Tony!!! :seeya: