[Alireza]

I need an auto-transfer switching control diagram for use in main-emergency power supply system. Can anyone advise me?
I need an auto-transfer switching control diagram for use in main-emergency power supply system. Can anyone advise me?

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[Hamid]

You can refer to Changeover device to DIN VDE 0108

[buchio]

good day sir Can i use a contactor to connect automatic changeover transfer switch?

[Hamid]

Yes, Q11 and Q12 in above circuit diagrm are contactor.

[Abdussalam]

Hi,,, I Have Gen-set and would like make a ATS between Main line and generator, so I would like to send me a simple Diagram and colored pictures for each item and how connected them by diagram wires. Thanks too much

[Alex]

Hello all, I want to use this electrical diagram to design some electrical panels. Thank you for this simple and good diagram. I will add also two delay relays to connect the main/ the generator delayed. I have one question, appreciate if you can help me. I will use this ATS to feed 3-phase loads but also 1-phase loads. How can we connect the single phase loads to the neutral and earth? If we connect the loads to both neutrals/N and earth/PE (mains+auxiliar) this means we connect the main N to the auxiliary N and main PE to the auxiliary PE . Is this correct and safe to do? Connecting the main and auxiliary in parallel is not allowed but to connect the N and PE in parallel is allowed? Another idea would be to use 4-pole contactors (to disconnect also the neutral) but unfortunately our approved supplier have only 3-pole contactors.

[Hamid]

Generally in electrical system with multiple neutral-to-ground connections, (e.g. the main and Standby/Emergency power supplies) the neutrals of the two systems must be separated to assure proper ground fault current sensing. When the separated ground fault in two systems is mandatory, the incomplete sensing and nuisance tripping can be eliminated by 4 Pole transfer switch application, which will also classify the Standby/Emergency supply as a separately derived system. On the other hand some standards such as Canadian Electrical Code does not require, nor is it general practice to provide additional ground fault protection where the essential loads are energized from a separately derived power system, such as an engine-driven generator set. However according to some recommendation no ground fault protection is applied to any emergency system where the capacity of a generator is 500 kW or less. This is a trade-off in possible electrical equipment damage, in order to keep the essential circuits in operation, as decided by an operator. Therefore if individual ground fault protection is your concern you shall use 4 pole transfer switch for suitable neutral/ground separations.

[Author]

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