Why am I not getting power to the unit and the power cord will not reset?

Question edited for a lot more clarity.

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Probably this one. Talk to your installer.

https://www.amana-ptac.com/products/ptac/hec154j

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Hi,

Please ask him to use the manual for the product in order to understand how to add the cord back on. If this does not work, please call the company to get a different perspective on the matter. Their phone number is: 1-800-541-6645 . Thank you.

I think you've gotton your moneys worth with ten trouble free years. The power cords safety device is a bit more sensitive to a high resistive short to ground than your breaker is. I would suggest that there is exactly that: a high resistive short to ground within the cabinet of the PTAC. It has been years since I have been on a PTAC call and am unable to suggest specifics. But if you are competent and capable of using a DVOM, open up the unit and begin a systematic approach of determining the problem.

The FIRST thing I'd do is check the motor and the compressor with a digital megohmeter. Sometimes their problem will only show up with this sensitive device.

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I found a few on line. You can propbaly find more choices. Do a web search for "Friedrich 42" PTAC air deflectors".

I don't see this error code in the manual. I do see nP as an error code for Window Switch lockout. I just had this happen to me and they had me reset the control board.

Remove case, flick master switch to OFF for 10 seconds. Press Heat/Cool same time turn switch back on HOLD until off light comes on.

You should be fixed. Just had to do this for my unit. I was playing around with the settings and turned on the window switch option by accident.

did you check the reset switch on the power cord

The 265/277v units will not work in a 208/230v hotel without a transformer. Basically you do not want to get involved with that. When replacing your PTACs stick with the proper voltage. As far as a conversion kit, if one exists, the cost will put you right back at the cost of a new unit. If your hotel is wired for 208/230v it won't give the unit the power it needs to function properly. When looking for replacement units here's what you need to match (besides getting the proper BTUs):
Voltage
Unit size (make sure they fit in your existing sleeves)
Power cord configuration (the 265/277v will have a different power plug)
Good Luck!

I know this is late but I had to add a solution to this problem since I had the exact same problem and was able to solve it. The probelm is not your control board. On these units, the heat pump compressor will not kick in unless the temperature you set on the control panel is within 2-1/4 degrees (or 4 degrees depending on your unit model. Otherwise, the unit locks out the compressor until the electric heat coil bring the indoor temperature up to that level - and then will switch the compressor back on for heat pump operation. So the problem is not the control panel or the compressor, it the electric heat coil. The coil has two manual limit switches on it that may be tripped and should be checked. The coil can be easily accessed by shutting down the power, removing 4 screws around the air outlet, pushing the screen up and sliding the panel out the top. The power wires can remain in place while the limit switches are reset. Hope it works.

If you have a clamp tester, operate the unit with the clamp tester and check the current reading. If the current reading is normal but the reset button is tipped then there is something wrong withe power plug reset button. But if the current reading is higher than the name plate rating then there is something wrong with the unit.

You need to replace your control board, but if you are can repair it by your self you can change the relay that supply the fan and condenser.