Hi Everyone,
Before I start, a quick question. Is there anywhere I can buy an off the shelf power factor correction devise sized anywhere between 60 - 80 micro farads? If not I will have to attempt to build one myself. So here goes...
I have a slush machine which is primarily a compressor/motor. My power meter shows a power factor of 0.6 its true power is about 1100 watts and its drawing about 8 amps of current. This is for the UK with 230 volts AC and 50Hz
I would like to correct the power factor towards 1 so I can add more slush machines to the same line without having to upgrade the line which would be very difficult to do as it would require removing the flooring. If my calculations are correct I need an 80 micro farad capacitor to bring the power factor towards unity. Can one of you please confirm I have the capacitor size correct?
I was thinking of wiring the capacitor to a plug with a bleed resistor inside the plug.
A bit like in this youtube video. You can skip to 1 min into the video to see what I mean
Unlike in the video which has multiple capacitors I was thinking just have 1 x 80 uf Capacitor and the load both on the extension lead and that connected to the mains.
I have a few questions.
What size should the bleed resistor be? Is there a certain specific type of resistor I should be using? I have found the following website which has a 52,000 ohm 3 watt metal oxide power resistor. Would that be the correct type and sizing?
https://www.rapidonline.com/truohm-3w-metal-oxide-resistors-5-66471
An online capacitor discharge calculator says it would take ~10 seconds to discharge from 300 volts to 30 volts using a 52,000 ohm resistor. Would 8 seconds be considered sufficiently safe or should I size a faster bleed resistor like 22,000 ohm which the online calculator says would take ~4 second to discharge from 300v to 30v.
Can I put the bleed resistor inside the plug or will it heat up too much and melt/burn or otherwise cause a problem if installed inside the plug?
Is there anything I have missed or not considered?
Also to note I believe there is a start capacitor inside the slush machine already, will there be any problem or interference or something I am not aware of if I correct for power factor on the line?
Also what would happen if the mains line was disconnected for a few seconds and then reconnected. Would the capacitor discharge rapidly into the mains causing a spark or any problems?
Will this power factor correction interfere with the RCD or trip it in any way. (my guess is no but its best to ask)
Any help and advise greatly appreciated
Many Thanks
Kaya
Before I start, a quick question. Is there anywhere I can buy an off the shelf power factor correction devise sized anywhere between 60 - 80 micro farads? If not I will have to attempt to build one myself. So here goes...
I have a slush machine which is primarily a compressor/motor. My power meter shows a power factor of 0.6 its true power is about 1100 watts and its drawing about 8 amps of current. This is for the UK with 230 volts AC and 50Hz
I would like to correct the power factor towards 1 so I can add more slush machines to the same line without having to upgrade the line which would be very difficult to do as it would require removing the flooring. If my calculations are correct I need an 80 micro farad capacitor to bring the power factor towards unity. Can one of you please confirm I have the capacitor size correct?
I was thinking of wiring the capacitor to a plug with a bleed resistor inside the plug.
A bit like in this youtube video. You can skip to 1 min into the video to see what I mean
I have a few questions.
What size should the bleed resistor be? Is there a certain specific type of resistor I should be using? I have found the following website which has a 52,000 ohm 3 watt metal oxide power resistor. Would that be the correct type and sizing?
https://www.rapidonline.com/truohm-3w-metal-oxide-resistors-5-66471
An online capacitor discharge calculator says it would take ~10 seconds to discharge from 300 volts to 30 volts using a 52,000 ohm resistor. Would 8 seconds be considered sufficiently safe or should I size a faster bleed resistor like 22,000 ohm which the online calculator says would take ~4 second to discharge from 300v to 30v.
Can I put the bleed resistor inside the plug or will it heat up too much and melt/burn or otherwise cause a problem if installed inside the plug?
Is there anything I have missed or not considered?
Also to note I believe there is a start capacitor inside the slush machine already, will there be any problem or interference or something I am not aware of if I correct for power factor on the line?
Also what would happen if the mains line was disconnected for a few seconds and then reconnected. Would the capacitor discharge rapidly into the mains causing a spark or any problems?
Will this power factor correction interfere with the RCD or trip it in any way. (my guess is no but its best to ask)
Any help and advise greatly appreciated
Many Thanks
Kaya