Standby Generator

[kana]

Hi,

 

I have an application where a single generator needs to backup three different offices during power failure. Since all three offices have their own incoming supply, I have suggested to use 3 different automatic changeover contactor set which will connect the generator supply to any of the offices during a power failure. Is there any drawback with this design?

 

 

 

Regards,

 

Kana

 

 

[yuri]

Hello Kana.

Would not it be more simple (and cheaper) to rearange commutations so as to unite the offices' supplies?

[kana]

Hi Yuri,

 

All three offices have its individual KWH meter. It would be more expensive here if we were to unite the supply and request for 1 KWH meter. We must also modify the existing wiring and switchboard to suit our new requirement. So to unite the supply will not be a good option.

 

Regards,

Kana

[yuri]

Hello Kana.

 

That there is common supply does not mean there should be a common meater - every office mighrt preserve its own one. I meant also cables are cheaper than electronic appliencies - the more so if the offices are not too far away from each other. Major drawback here would be if a fault was internal to an office - then the other two would suffer from need of switching to back-up supply.

 

But someone should come up with a better idea.

 

All the best to you.

[HienN]

Hi,

 

I have an application where a single generator needs to backup three different offices during power failure. Since all three offices have their own incoming supply, I have suggested to use 3 different automatic changeover contactor set which will connect the generator supply to any of the offices during a power failure. Is there any drawback with this design?

 

Regards,

 

Kana

 

Hi Kana,

 

Your design sounds right and I have not any better idea. I just suggest some more thing that should be considered about.

 

• As Yuri comment, it depends if the 03 offices are located far away from each other or not.
• If the No. 1 is solved, then at three inlets of incoming supply should equipped with 03 under-voltage relays each of the office and 6 pieces of contactors (2 pieces for 01 office). If the fault happens at the main power line of one office, the Power generator will feed backup to this area only while the other two remains the same due to the relay does not sense any under-voltage at all. Power is also available at the other 02 backup contactors.
• Each of relay will sense the voltage in the system that feed the three buildings.
• Be sure that these offices has separated power supply. (not to return the power back to the source when power generator is in operation).
• Each of relay will in parallel send the starting signal to power generator and then close the off-power branch's contactor.
• We also need some timers, auxiliary relays for the control circuits.

 

Post up here what you are you thinking of.

 

Good luck,

 

Hien

[kana]

Hi HienN,

 

All three offices are located on the same floor of a high rise building. Supply is fed by a tap off unit to the individual KWH meters. Then from the meters, the cable travels to individual distribution boards. My idea was to have 3 sets of automatic changeover contactor connected to a common genset. My idea is similar to what you suggest.

 

Regards,

Kana

[HienN]

Hi HienN,

 

All three offices are located on the same floor of a high rise building. Supply is fed by a tap off unit to the individual KWH meters. Then from the meters, the cable travels to individual distribution boards. My idea was to have 3 sets of automatic changeover contactor connected to a common genset. My idea is similar to what you suggest.

 

Regards,

Kana

 

Hi Kana,

 

Let's go with your idea. I am here and looing forward to hearing from you the good news.

 

Regards,

 

HeinN