Rule of Thumb for Sizing Breaker for Future Capacitor Bank and Active Harmonic Filter 1

[Pgee630]

HI,

May I know if there is any rule of thumb to reserve the breaker provision for future capacitor bank and active harmonic filter in an electrical system - i.e. sizing the breaker for the future cap bank and AHF. The reason is that at the moment of design, we don't have any information about the terminal equipment to be installed so we don't exactly know the power factor and harmonics data.

Thanks for advices.

 

[che12345]

Dear Mr. Pgee630 (Electrical)(OP)
Please tell us a little more about your situation/installation:
1. The installation is in IEC or US/ANSI world?
2. The system is a [LV <1kv] or a [MV >1kV]?
3. Does the billing (a) includes a penalty on low power-factor or,
(b) based on the kWh consumption only, where power-factor is NOT recorded.
4. FYI: Most utilities do NOT penalize (small industrial consumers) taking LV supply; running on [low power-factor]. In this case, consumers usually ignore the Cap bank, for improving the power-factor of their installation.
Che Kuan Yau (Singapore)

 

[Pgee630]

Hi Che,

The installation is based on IEC, a LV system, there is low power factor penalty imposed by utility company. Thanks.

 

[che12345]

Dear Mr. Pgee630 (Electrical)(OP)12 Sep 22 17:27
"...May I know if there is any rule of thumb to reserve the breaker provision for future capacitor bank and active harmonic filter in an electrical system - i.e. sizing the breaker for the future cap bank and AHF....there is low power factor penalty imposed by utility company..." .
1. Suggestion: either (a) have an empty cubicle reserved for future use , or (b) reserve a space to place the future cubicle.
2. The number of Cap bank and size VAr would increase as the load increases gradually. As an indication, the final number and size may be based on 0.6 improve to say 0.9.
3. In general, a six step regulator would be fine.
4. Reserve room for one Breaker and say 6 sets of [fuse, capacitor contactor , Capacitor and AHF].
5. As an indication: one cubicle say 2mH x 800mmW x 1mD would have sufficient room to house the items mentioned in above No. 4.
6. Attention: provide large incoming and outgoing natural ventilation openings !. The Cap bank + AHF are going to produce very much heat.
Che Kuan Yau (Singapore)