Purchased new air conditioner for bedroom. Installers bypassed SafeTCut saying it was not needed. Supposedly his air conditioner already had a trip switch. Brand installed was Mistubishi Mr. Slim. The main line into the house is located directly above the bedroom and the SafeTCut box is located in the middle of the house. Part of me thinks installer connected to the direct line into the house because it was easy and convenient. I've never heard of connecting directly to the main line and bypassing the breaker box.

We purchased one other airconditioner 2 years ago from this same business. Happy with their service, so purchased this second one. As far as I know the first one was run through the SafeTCut. We are repeat customer, so would be very surprised if they would do something so foolish as to bypass breakers if they are really needed. The owner of business was on site when installed and was the one who told us SafeTCut not needed.

They did install a flip on/off wall switch that cuts the power to the air conditioner. Previous air conditioner they installed has same. Maybe there is a trip switch inside this wall box.

Had another recent experience buying furniture. Purchased many furniture items from a business, but recent custom order was not what it should have been. They said would correct next day, but haven't showed up or called. Starting to wonder if repeat business is even important to Thai businesses. Because I'm falang or do Thai customers get same treatment.

Anyway, SafeTCut or not to SafeTCut an air conditioner?

Thanks.

They cut corners because it was easy.

Every appliance in the house needs to go through the central fuse box at the very least.

Not sure the air-con unit needs a T-cut, as it's not something you are ever likely to accidentally touch.

But it does need to go through the fuse box.

Having an unfused appliance means in the event of an extreme electrical fault, in said appliance, it could burn your house down and you most likely won't be insured.

Just looked at the wall switch I mentioned in my original post. Says "safety breaker." Looks like businesses are installing their own breaker to avoid having to go through the SafeTCut box. A shower water heater we had installed has this same switch box on the wall. Just looked at it and it says "20 amp safety breaker".

Are these individual breakers sufficient enough to bypass the SafeTCut?

Thanks.

Yes for the A/C. Maybe not for the shower - if it has "ELCB" then marginally OK. As someone else said, they really should be using circuits from the CU but splitting off to non-RCD (usually to a separate CU) things like A/C and water pumps is "normal".

No protection from ground fault if not used - that switch is just a normal switching breaker and offers no ground fault protection (Safe-t-cut function). A shower will normally have a built in breaker ELCB with fault protection as part of the wall unit. As air conditioner compressors are like refrigerators and often start to have some ground leakage as they age many installers do not want to put on a protected circuit to avoid trouble calls later. In no case should any connection be made prior to main house fuse/breaker - a fault of that wall breaker or contact on input would be a major hurt.

Had a lot of trouble with the installer of ours who is from a leading firm and an actual Mitsubishi service agent,. Tried to tell me that no earth was needed and that f I had one lightning would damage the unit. Our very good local electritian ended up taking them to task for it as he proved to them the case was live.Tnen they tried to install a second earth rod and not use the house one. DId not believe the Electricity Department Rules we showed them that required only one earth for a building. Not happy,