three phase motor energy saver

[clarke]

Hi
We have four energy saving devices (Atto power misers) fitted to 75kw motors, we have two mcc's fitted with two power misers each, If one of the powermisers has the mccb switched off then back on whilst the other powermiser in the same panel is till running that powermiser shuts down, a similar effect happens when the powermiser starts up. All control cables running to the powermiser are screened and run seperatley from or where not practical to run seperatley at 90 to power cables.

 

[cbarn24050]

Hi, put suppressors on your contactor coils (VDR or RC or both).

 

[jbartos]

Suggestion: Visit

http://www.powermiser.co.uk/

for Virtual Powermiser
Apparently, it may be a good idea to simulate the PowerMiser applications first.

 

[clarke]

the power misers are all solid state and have no contacors fitted.

 

[ScottyUK]

Clarke,

Sounds like one of the units is being affected by voltage fluctuation when the other is switched. How stiff is your supply? 75kW is a fair load to switch, especially if it is in an MCC located some distance from the distribution transformer. Is this problem an HVAC system with a roof-mounted plantroom by any chance?

Suggest you get a 'scope with an isolation probe (or an insulated scope) and see what happens to your local supply voltage as you switch the drive on or off.

 

[jbartos]

Suggestion: Powermiser tech support would be appropriate for assistance during troubleshooting.