Capacitors

Robert O'Brien

Any suggestions for truck stock? 2-5 ton residential systems.

James Day_2

Capacitors

I stock 5, 7.5, 10, 12.5uf capacitors for air handlers.

30/5, 35/5, 40/5, 45/5, 45/7.5, 50/5, 60/5 for condensers. They also sell the multi-tap capacitors that cover a wide range.



Hope this helps, James

Techman

Caps

Robert, start a list of ALL the caps you run across in all of your customers units.See whats common for your area.Between single oval run caps both 370vac &440vac ,dual oval run  caps both  370&440vac ,  round single run caps both 370&440vac and round dual run caps both 370&440vac ,that adds up to 110-120 common run caps on board for us. Let's not forget that Start Caps are real popular these days, and there are "common "start caps ,too! And there are common potential relays which go with those common start caps.

Paul Fredricks_3

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I like James list. And as far as voltage goes, you can use a 440V cap instead of a 370V, but not the other way around. For MFD's it's +or- 10%, I think.

Techman

Caps

Paul,I agree w/ you on  James list. But its only recently [10years or so]that some 440vac run caps are physically close/same as the 370vac run caps, so, a lot of the "older" 440vac run caps would not fit into those extremely tight control panels where a 370v cap is/was.There are lots of cond units out there that have seperate caps oval/round oval/oval for the comp & cond fan motor. On some of the  cond units that have round holes in the control panel for  round caps, you can/will have a hard time safely laying  in an  oval cap in its place in the control panel so sometimes  the replacement cap is attached outside the control panel. And then there are units w/ oval holes.

Paul Fredricks_3

I hear ya

Don't see to many with the holes around here. I can't remember the last time I had a problem fitting a capacitor in place, but maybe I have more 370's than 440's on the truck. To be honest, I haven't looked. The biggest problem I have with caps is they move around so much on the truck by the time I go to use one I can't tell what it is.

Is it safe to say smaller tonage units use 370's? I never really done an analysis. If that were the case then smaller caps at 370V and larger at 440V.

Techman

Caps

Good question Paul, I'm going thru the Copeland Handbook to see if the 370vac caps are for smaller tonnage comp's and the 440vac caps are for larger tonnage AC units . My goofy memory is saying "it ain't necessarily so" but some research will tell. I'll get back to you on that ,give me a couple of weeks.

Eugene_Silberstein

Capacitor Voltage

The voltage rating on the capacitor is not the voltage that will be discharged by the device, but the maximum voltage that the capacitor should be exposed to. So, back in the day, I would stock my trucks with 440V capacitors instead of 370V devices. This way, there was never a problem with a technician installing a capacitor rated at 370V when the original was rated at 440V.



Just for the record, capacitors wired in parallel with each other will result in a total capacitance that is equal to the sum of the two capacitances. So, two 20uFd capacitors in parallel will give you the equivalent of 40uFd. From the good old days of basic electricity, capacitors in parallel add up as resistors in series do, and capacitors in series add up as resistors in parallel do.



Have fun!

meplumber

James list

Our vans stock a list pretty similar to James'.  We don't keep 5's on the truck and maybe only one or two 7.5 for blower motors.  Most of our stuff is large commercial and institutional.  I like the multi taps, but don't completely trust them.  We use them to get out of a jam, but always replace them with the correct cap as soon as we can get one.

Techman

Caps

This info is out of the Copeland Product Guide for their 1 1/2 - 5 ton  "K"  Scrolls. They show a 370vac @ 1 1/2 -5 ton on the "K3" model and on the KC model a  370vac on the 1 1/2 ton w/ a 440vac cap on a 2ton -4ton  and back to 370vac on the 5ton.So ,Paul. I'm going to say no.

Paul Fredricks_3

oh well

It was worth a try.

drhvac

I agree

with what some of the others have recomended for what size caps to stock, but I only get 440 volt caps. You could use them to replace the 370v caps, but you cant replace a 440v cap with a 370v cap. The price is just about the same, and its a lot less to stock instead of having both voltages.

Techman

Truck stock capacitors

Hay Robert, how did you find your truck stock of cap's this summer? Did you add any new caps to ur truck? Did you have to run to the supply house to get just a cap for a given customer? I added 5-7 new caps this summer myself.

Techman

Caps

I have a 50/440 run cap that is 4 1/2" x 3" x 8 1/4 "  but thats not truck stock and the cap doesn't seem to fit into most cond units!