ECD - tried servicing and now all temperatures are affected

[Peter Apps]

Given that your power supply may not be the cleanest, one of these http://en.wikipedia.org/wiki/Varistor might be worn out. When degraded they look fine. We had wiring issues - ours did not look anything like fine !

Peter

[lusi]

Thanks Peter. And you are right about our power supply not being the cleanest. I was shocked to see dust on the thing.

I forgot the technician was saying maybe another part was damaged and it in turned caused the fuse to get damaged. Is this possible?

Also he currently does not know what the particular fuse controls, so I think the next move for him is to contact the manufacturer.

[Peter Apps]

Hi Lusi

Sorry I was talking about the supply of power - the mains electicity not being clean - voltage fluctuations, spikes and power cuts etc.

When our MOVs did their job by bleeding a voltage pulse to ground one fuse also blew - presumably in response to the extra current.

You might get more sense out of a local television repair shop than the instrument service technician.

Peter

[lusi]

Thanks for the clarification Pete.

I asked him about the varisators (they call them by a different name) and he indicate that should not be a problem since they were never regulated.

We do have a 8KVa UPS, which theorectically should prevent us from having damage from electrical surges etc. However, the technician advised that I have a diagnostics done on it anyway. Not sure if some damage was done when the unit was attached to a previous UPS and they are now surfacing. We have changed a couple of boards even though the unit was not working to full capacity and even turned off for fairly long periods due to various reasons.

Well the technician is saying at this point in time all he can do is take back the board and then maybe try to fix the problem there. He tired to isolate the problem other than the fuse but was not able to do that.

Also the individual from the factory who might be able to better advice is out for the week. So I guess we may have to wait and see what occurs.

[Peter Apps]

Hi Lusi

We too have a big UPS - problem was that the building wiring was wrong. Assuming that you have 3-phase power somewhere in your building there is a possibility that you have something like 400V between live and neutral instead of 230 V (or whatever your local line voltage is supposed to be. According to the imported expert who finally figured it out all the neutral wires must be connected together, and all must be earthed. Get an electrician to check it all out.

Sad to say, in your case, I still think that you might have dmaged something when you were working on the ECD.

Peter

[lusi]

Hi Pete, I think we had that wiring problem too with our first UPS and it blew. The same company came back with a different UPS.

I think something might have been damaged during working on the ECD, but we dont know what yet. And because so many boards over the year came down the technician is just suggesting that we have it checked out anyway.

[Peter Apps]

Hi Lusi

If you have a problem with your mains wiring then changing and replacing blown components and UPSs is a pure waste of time and money. You need to have your electrical supply checked out by a competent electrician, and if there is a problem get it fixed before you even think about replacing components of intruments.

Peter

[lusi]

Hi Peter, We did have our electrical system looked at earlier in the year. It was overlaoded and overheating, and so automatically causing black-outs. Since then the only problem we have had with that was having the fuse controlling two sections of the building blowing. But I think that was all due to the electrical problems with the power company. Since one of their fuses got damaged and caused a black out.

Generally we are sick of the power company. They are claiming they are doing repairs and that is why we have all the power fluctuations and black-outs. And less than six months ago they were apparently upgrading the system and we had the same conditions.