I purchased a Campbell Hausfeld 6 hp 60 gallon DK400121AV. It's supposed to run on 240v, but the guy I bought it from had a 120v plug wired to it. How do I wire a L14-30P plug to the pressure switch?

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  • 4
    Whatever you do, fix the wires so they’re attached to the screws correctly: being pulled in when the screw is tightened, not pushed out. The black “line” wire is done correctly, the white “line” wire is wrong.
    – nobody
    Commented Dec 11, 2023 at 13:42

3 Answers 3


Before you get too far, make sure the motor itself has been switched back to 240V operation. That typically involves certain jumpers being connected differently than how they are for 120V operation. Possible the prior owner was supplying 240V via a 120V plug, but in any case, check, before you do damage to the motor.

As for the pressure switch and an L14-30, you have no use for Neutral here, so the two hots from the L14 plug go to one side of the switch, which says "line" and the two hots to the motor go to the other, which says "motor"

The ground goes to the ground connection. Repeat - Neutral is not used here.

If you're not constrained to an L14-30 (looks like you might be trying to power it from a generator with one?) an L6-30 or 6-30 would do the job. Though depending on the compressor motor draw at 240V, could be a L6-20 or 6-20 would be sufficient.

  • Yeah I’m using a Westing house Wgen9500, it doesn’t have a L6-20 outlet. Compressor is a CH 6 hp 60 gallon DK400121AV
    – Andrew
    Commented Dec 11, 2023 at 2:20
  • 100% agree with your first paragraph about motor jumper configurations. Not sure yet if I agree with you saying neutral is not used here. Please see my answer. Commented Dec 11, 2023 at 11:25
  • 1
    @Andrew Campbell Hausfield's website doesn't recognize that model number, so it's hard to tell if there is an alternate 120v input as Aldus Bumbledore suggests. Commented Dec 11, 2023 at 12:35
  • @Triplefault yes I noticed that on the CH website also. I was wondering if the site would find an older discontinued model though. If my suspicion is correct I think you will not be able to tell from the website except by chatting with an agent. This is a large commercial size and OP may be unfamiliar that such things often don't bring their own cord. Commented Dec 11, 2023 at 14:15
  • What we can see is two terminals marked LINE, two terminals marked MOTOR, and one ground terminal. If there's a weird 120V connection with neutral, it's not shown here. And the OP does not mention two power cords.
    – Ecnerwal
    Commented Dec 11, 2023 at 14:20

The following answer I believe is wrong for this OP, but maybe it will help someone else in the future.

Are you sure that "110v plug" is really the main power input for the compressor? I recommend making sure, particularly with this brand.

At my workplace 6 years ago in 2017, we ordered a Campbell Hausfed compressor new. It was a 3 phase 208 model model CF7053FP. A similar size to yours, but with horizontal tank. Imagine my surprise when it showed up with a NEMA 5-15 plug (yes, a "110v plug"). Turned out the motor was 3 phase 208 but apparently CH saved a few dollars by powering either the dryer or the pressure switch (I forgot which) with a separate 5-15 cord.

The "actual" power input for the motor was terminals inside an electrical box on top of the tank. Large commercial products like this typically do not come with a power cord. If you buy a used unit, very likely the seller will not include their power cable. The cable is a separate product that they bought, so they may be disinclined to pass it along to you unless you negotiate it.

In my case, we had to return the compressor because we had intended it for use in an area with no neutral. I studied all the literature available on their website to find where I went wrong so I would be sure not to make the same mistake again. I had to conclude the additional power requirement was completely undisclosed. It was their mistake to make the assumption that a customer with 208 would always have 120 available, and that they didn't need to disclose it on the spec sheet or instructions.

I found my notes on that debacle, but my "notes" are nothing but a bunch of screenshots and literature I collected in an attempt to show that the extra power requirement was hidden from prospective purchasers. I was ready to offer backup to my credit card holder if there was some kind of billing dispute. Fortunately the return process was easy, and I selected a replacement of another brand which turned out fine.

  • Note: In 2017 (and for several decades prior) the US electrical grid supplied 120v, not 110v or 115v. Well, 120v is the design spec, power fluctuations could drop it to 110-115v...
    – FreeMan
    Commented Dec 18, 2023 at 13:26

The L14 plug will have 4 connection screws labeled G, W, X, and Y. You will not use the W (silver colored) screw. The X and Y screws will connect to the pressure switch on two screws labeled LINE. Green ground G severe connects to ground on compressor.

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