Tip & How-To about Refrigerators

How to: connect a hardstart on a compressor

The compressor has 3 terminals, start, run, and common. The black wire always goes to common. The white wire goes to the left and the red wire goes to the right. Note: It is always best to go with the correct relay for the compressor but in a pinch or if you cannot get the correct one you must use a hard start device.

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Please identify compressor connections. Original = red to low, white to high left, nothing on high right. New 3n1 has black (common) and red (run) white (start) and twin black power lines.


The three compressor pins are shaped in a triangle, the common is either directly on the top or directly on the bottom depending on the compressor. The wires of the supco are installed with the red to run, the white to start,and the black to common.(If the common is directly on top, run is lower right and start terminal is lower left) (If the common pin is directly on the bottom, the run is on the upper left, and the start is on the upper right) When you cut out the bad relay overload, the wires hook on the two black wires of the supco with bare ends.

Check for full 120 volts at the outlet, important.
If you have a meter you can ohm out the compressor windings, the run and start are connected to the common. It is easier to explain looking at a picture, so good luck.......... Picture a triangle with three letters c for common, r for run, and s for start........

The other thing to remember is there is a new type of compressor(some variable speed new one I am unfamiliar with) that does not use this setup, check the schematic(95% will) Consider if you still have a warranty on the compressor also. Supco also sells a 3n1 with a hook up for the old capacitor on its part, very handy, just plugs on, you do not mention it, so probably not the one you have. If you get your compressor running and it sounds good, do not buy a fridge full of groceries for a week or so, compressor may fail, let it run for a few days first, hope this helps,
good luck and do not forget to unplug when working on it..........

This is basically general information for a older refrigerator out of warranty....
Also consider the possibility of what could go wrong if you are not sure of your work, do not attempt this if there is a strong burn mark from old electrical s, replace compressor and or buy a new unit.

Mar 16, 2011 | Whirlpool Refrigerators

1 Answer

need to wire cap


I am assuming this is a combo fan and compressor capacitor.
In american air conditioners the cap has 3 sections all clear marked. The fan has an F and only 2 terminals, the compressor has a HERM (for hermedically sealed compressor) and only 3 terminals. The cap also Has a C for common with 4 terminals. What you want to do is connect a start wire from the fan which is usually a small plain brown wire to the F terminals. You would want to connect a start wire from the compressor which is a heavy wire to the Herm terminals. Then the compressor and fan both have a common wire those go to the C along with one side of the Power cord. The fan common wire can be purple or white. If you decide NOT to use the white wire for common you be sure to tape it off. Then you can use the brown wire with the white stripe fro common. The other side of the power cord will receive the RUN wires from the fan and the compressor. Note: If the fan has multiple speeds you must ONLY connect one speed at a time. Speeds are normally Black for high, Blue for medium and Red for low. So if your intent was to maybe bypass a switch or board you would tape off the blue wire and the red wire seperately and use the black wire for a high speed fan.

Oct 27, 2010 | Heating & Cooling

2 Answers

I have a 3 terminal electrical connector dryer and need to replace with a 4 terminal connector. I went to home depot and got a 4 terminal connector that has a balck,green,red,and white connector but when I got home and opened the dryer back, there are only 3 places for terminal connectors. Will my Maytag dryer not convert to a 4 terminal or what do you recommend?


The green is ground, white is neutral, red and black are both hot (L1 and L2). If you put a 4 prong pigtail on, remove the ground strap between the center post and the case. The green ground goes on the case, white neutral in the center, black or red to the left, what's left on the right. You can interchange the red and black but NOT the white or green.
For safety's sake, put the Red on the right post, white in the middle, and black on the left. The green gets grounded right to the case.

Jan 02, 2010 | Dryers

2 Answers

Compressor problem, installing the Supco 3-in-1 Relay


Hi, If the 3 posts are top center and bottom right left, the black wire goes top the top center post. The red wire will go to the bottom right and the white goes to bottom left.
If the posts are bottom center and top right left, the black goes on bottom center and the red goes top left. The white goes top right.
If you do not see a capacitor, disregaurd the wires in the 3-1
I hope this helps you. Please let me know if I can assist you further.

Vic

Jul 02, 2009 | Maytag SkyBox MBV1976A Beverage Dispenser

1 Answer

Wiring compressor


The two terminal cap is only for the new fan motor. Connect the compressor wire back where you found it, on the 3 terminal cap. It's the terminal marked, "herm". The "common" terminal on the 3 terminal cap must still be connected to one side of the 220 power at the contactor. One side of the 220 goes to the common on the compressor. The other side of the 220 goes to the run winding on the compressor AND the common terminal on the 3 terminal capacitor.

Jul 18, 2008 | Carrier 38CKC036 Air Conditioner

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