AJJewsbury:I still don’t know why switching a 100w lamp on/off would have such an effect
I would have expected an incandescent lamp to have much more of an effect when being switched on rather than switched off - since they have quite low resistance when cold the 'switch on surge' can be relatively high - for a small fraction of a second more like connecting a 1kW load rather than a 100W one.
The reason for asking about any upstream UPSs or PF correction was the though that even relatively small changes in load (either current or PF) could cause things that are only just within one state to switch to another - e.g. switching capacitors in/out in a PF correction unit or causing a UPS to monentarily switch to bypass - and that switching, especially if faulty/dirty contacts could cause a lot more problems than would be expected from the load itself.
- Andy.
Hi Andy,
I think the lamp was worse on the scope when switching on for sure, but it definitely effected it switching off too.
I am still a little suspicious of the PF correction unit but not sure what to physically check at this stage but I will take a closer look.
AJJewsbury:I still don’t know why switching a 100w lamp on/off would have such an effect
I would have expected an incandescent lamp to have much more of an effect when being switched on rather than switched off - since they have quite low resistance when cold the 'switch on surge' can be relatively high - for a small fraction of a second more like connecting a 1kW load rather than a 100W one.
The reason for asking about any upstream UPSs or PF correction was the though that even relatively small changes in load (either current or PF) could cause things that are only just within one state to switch to another - e.g. switching capacitors in/out in a PF correction unit or causing a UPS to monentarily switch to bypass - and that switching, especially if faulty/dirty contacts could cause a lot more problems than would be expected from the load itself.
- Andy.
Hi Andy,
I think the lamp was worse on the scope when switching on for sure, but it definitely effected it switching off too.
I am still a little suspicious of the PF correction unit but not sure what to physically check at this stage but I will take a closer look.
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