ReplyYou can get them way cheaper at an electrical supplier than through Trane. Just go to your local ABB dealer and take the Cat#.
You can run without them but they may pay more to run it.
Regular Guest
I had a power factor capacitor blow up on a 460v starter for a trane cvhe. i disconnected both capacitors and the motor seems to be running just fine. is there any issue with just leaving them disconnected and not replacing them? they are strictly accessories , right ?
Professional Member
You can get them way cheaper at an electrical supplier than through Trane. Just go to your local ABB dealer and take the Cat#.
You can run without them but they may pay more to run it.
Regular Guest
thanks will do
Professional Member*
You can run the chiller without them but the chiller will use more power. They're accessories.
Professional Member*
post time- The motor operating the centrifugal compressor has a power factor of about .70-.85, that is the volts-amps that are actually being used as compared to the design volt- amps. The actual figure incurs losses due to inductive reactance. The PFCC's put a leading capacitive reactance to counteract these losses and bring your motor power factor up to .95-.99. Unity or a power factor of 1.0 would be detrimental to the motor so we never attempt for a unity reading. Your electrical provider puts penalties on commercial facilities with lower power factor as this a waste of energy that isn't being of beneficial use that they still have to provide to run your equipment. I totally agree with R123, get your applied voltage rating and somewhere on the original PFCC's there should be a KVAR number depending on your actual motor horsepower. Give them these numbers and you should be good to go. Good luck and be safe out there.-Geo: angel:
Once in a while everything falls into place and I am able to move forward, most of the time it just falls all over the place and I can't go anywhere-GEO
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That's a great explanation George.
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R-123- Now you've gone and done it, you're making me blush !-Geo
Once in a while everything falls into place and I am able to move forward, most of the time it just falls all over the place and I can't go anywhere-GEO
Professional Member
unity power factor correction is actually ok...it is the OVER correction that can be bad.
if you do decide to replace the capacitors, make sure that you are wiring them up properly. the capacitors should be on the motor side of the contactors...not the power side of the contactors. if you are not sure, contact a qualified chiller technician or electrician.
i saw a manufacturing plant that had capacitor banks everywhere. they also had a PFCC on the wrong side of the contactors of the chiller. as soon as the chiller shut down, the capacitors were 'correcting' everything else in the building. every once in a while, 'pop' goes a capacitor...sometimes 'BOOM' goes a capacitor.
"Right" is not the same as "Wise".
Don't step on my favorite part of the Constitution just to point out your favorite part.
Just because you can measure it, doesn't mean it is important. Just because you can't measure it, doesn't mean it isn't important.
Professional Member*
Jayguy- I try to limit any power corrections to .97-.99 where economically feasible by customers purse strings. When I took class's on this topic we were taught to never go to unity (1.0) or above because of over excitation and over speed. While we are discussing this I have a question for you. Wye-Delta, closed transition starter, PFCC wired to the load side of the 2M (run) contactor. I would think Load side of 1M (starting) contactor would put them online sooner. I have seen them all over a central plant including switch gear way ahead of the starter for each individual chiller. The ironic part was these were either electronic soft starters of VSD Yorks. I tried to explain to the customer that he didn't need PFCC on these units and showed him in the York literature where the factory had said thats a no, no. If you can get a good motor reaction from unity without damage to equipment more power to you, literally.
-Geo
Once in a while everything falls into place and I am able to move forward, most of the time it just falls all over the place and I can't go anywhere-GEO
Professional Member*
this thread is a good read, one of the best I've read here.
Saving the world...one service call at a time.
Professional Member
i guess my point was that unity is OK by definition. if i found a unit running at or near unity, i would not be worried (because i am not liable for it), however, i would not engineer to unity without a very good power quality study...even then, i would still not correct to unity. typically, correcting to 90-95% is what i find stated in most manufacturers manuals.Originally Posted by ga1279
as for the wye-delta, i would wire it to the 2M only because during the start up, you may be over-correcting (even if it is only for the few moments before transition).
PFCC's between the utility and the starter are acceptable (although they are probably not needed) but between the VFD/soft starter and the motor is a very big no-no, however, some people do confuse 'filters' (which have capacitors in them) with PFCC's. this business is getting confusing and fun at the same time. i have learned a ton since i bought my Fluke 435!
"Right" is not the same as "Wise".
Don't step on my favorite part of the Constitution just to point out your favorite part.
Just because you can measure it, doesn't mean it is important. Just because you can't measure it, doesn't mean it isn't important.
Professional Member*
jayguy- That's about the way I size it up, Thanks for thw answer to the 2M question. I had a rather vivid discussion with an electrician concerning this point, he stated that being on the load side of 2M it was always in the circuit. I drew out the circuit in an attempt to explain that it wasn't, well you know the rest- Geo
Once in a while everything falls into place and I am able to move forward, most of the time it just falls all over the place and I can't go anywhere-GEO
Professional Member
i love electricians!
"whadda you mean 'phase rotation tool'? oh. i think that Jim has one. other than that, i have only heard of them."
1 phase rotation meter in an electrical contractor company is like 1 manifold set in a HVACR company.
"Right" is not the same as "Wise".
Don't step on my favorite part of the Constitution just to point out your favorite part.
Just because you can measure it, doesn't mean it is important. Just because you can't measure it, doesn't mean it isn't important.
Regular Guest
wow! you guys are impressive ! i was just wondering if it was ok to run the machine without them. i am glad i registered for this website and hope i can bring some sort of info to the table to help someone else . wait , blown fuse ? i got this one.......
Professional Member
as for running without them...
power factor correction capacitors 'store' the VAR's (Volts-Amps Reactive, sometimes called kVAR's or kilo Volts-Amps Reactive). when a motor runs, due to inefficiencies and other mother-nature type items, a certain amount of VA is sort of 'wasted'. the motor needs it. you have to provide it. but you don't get charged for it. why? because you and the utility play tennis with it. they make it, it passes through your motor, and then you send it back...simplified version. when you get it, your meter spins forward and you get billed because it is wattage (or kW). but then when you send it back, your meter spins backwards and you get a credit. now do this 60 times per second.
you get a bill for low power factor because it is wattage that the utility created but doesn't get paid for. because it is real wattage, the power lines and transformers have to be sized to carry it. so do disconnects AND OVERLOADS. but what if you could store it and stop playing tennis with the utility? PFCC's do this. they store it every cycle and then give it back to the motor every cycle. this removes the wattage from the lines and transformers.
cool!
but what if you sized your transformers and power distribution equipment and overloads without the kVARs? and now you are playing tennis again. transformers are now undersized. wiring is now undersized. overheating can happen. breaker tripping at full load may occur because they are now carrying the extra wattage.
the utilities have PFCC's in the lines that they can turn them on and off to correct for YOUR low power factor and your neighbors low power factor and his neighbors low power factor, however, they cost money to install, repair and replace. if YOU fix your low power factor and pay the costs, then they can actually give you a credit (if you correct the power factor high enough). i have 1 customer that gets PAID all winter long due to the high power factor they have. then the AC comes on and my customer starts paying them!
you will most likely be ok with this chiller...just be aware.
"Right" is not the same as "Wise".
Don't step on my favorite part of the Constitution just to point out your favorite part.
Just because you can measure it, doesn't mean it is important. Just because you can't measure it, doesn't mean it isn't important.
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