In one of my previous posts, I wrote about “Everything You Wanted to Know About Capacitors”, well, I didn’t give you everything I guess.
You all should know by now that you have to “match” the capacitance micro farad within the tolerance of the capacitor rating and that you can never go LOWER on the voltage rating.
Now, say you are at a job site and out of all the capacitors you have on your truck, none of them match and its 95 degrees outside on a Friday afternoon (or even worse — the weekend) and your customer HAS to have the air on because they are having a party. What can you do to get the air conditioner going for your customer?
Actually, there is one of 2 options you have if you have an assortment of capacitors of various sizes.
The easiest thing to do is take a bunch of capacitors and wire them in PARALLEL.
As you can see by the diagram above, by wiring capacitors in parallel, the micro farad become ADDITIVE so a 10 μF capacitor PLUS a 30 μF capacitor gives you 40 μF. The thing you need to be careful of here is that the VOLTAGE rating of the circuit is only as high as the lowest voltage rating of all the capacitors. You can string together as many as you need to make the micro farad you need to get the unit going. (personal comment -if you want to simplify your truck stock, keep ONLY 440 volt capacitors on your truck. Remember, you can always go higher but never lower)
The other thing you can do is to wire some capacitors together in SERIES.
The key to doing this is you have to use capacitors that have the same micro farad rating. When you wire capacitors in series, the micro farad rating is “halved”. The voltage rating is additive so the two 220 volt capacitors in the example above creates a 440 Volt 5 μF capacitor.
By either paralleling or putting capacitors in series, you can create the correct size capacitor you need to get the unit going.
In a lot of today’s units there are combination capacitors that handle both the condenser fan and the compressor. You can still use individual capacitors for each component. All you need to do is parallel the incoming power between the 2 capacitors and then just use the “discharge” of each capacitor to work with its component. You do not parallel the capacitor outputs, only the inputs.
Now I think I have given you “Everything You Need to Know About Capacitors”. — I hope this helps!