Easy Work Around or Not?

[JFletcher]

Been doing a lot of electrical work for a local hotel recently. I've noticed that quite a few of their PTAC units are 7k BTU, and come with 6-15 plugs, and are rated for 15A circuits. ofc they are on 20A circuits, above what the mfg requires (MCA 15A, MOCP 15A). 6-20Rs accept 6-15 plugs.

Is/was there an exception in older codes where this install was legal? There is one unit per circuit.

Eqpt is roughly 20 years old, place was wired in the late 60s early 70s. Quite a few of the plugs and/or receptacles have burned up, tho I believe that's more to do with them being not completely plugged in or mfg defect than the 20A breakers.

 

[dkidd]

Is/was there an exception in older codes where this install was legal? There is one unit per circuit.

No. They must be on a circuit with the required MOCP.

Not sure about the post title, but the breakers need to be changed.

 

[JFletcher]

That's what I figured. Was hoping since 6-20 receptacles can accept 6-15 plugs that there might have been (or be) an exception.

Changing the breakers is not really viable as 9 and 12k BTU units use 20A breakers, and they are mixed in with the 7k/15A units. Any time a change was made, the breaker would have to be changed too. Plus you can't put a 20A receptacle on a 15A circuit. Cheaper than buying new units tho. What a mess...

 

[growler]

Been doing a lot of electrical work for a local hotel recently. I've noticed that quite a few of their PTAC units are 7k BTU, and come with 6-15 plugs, and are rated for 15A circuits. ofc they are on 20A circuits, above what the mfg requires (MCA 15A, MOCP 15A). 6-20Rs accept 6-15 plugs.

If the manufacturer states on the name plate 15 Amp MOCP then I would install a 15 amp breaker if I was installing the equipment.

Otherwise I wouldn't worry about it.

 

[JFletcher]

If the manufacturer states on the name plate 15 Amp MOCP then I would install a 15 amp breaker if I was installing the equipment.

Otherwise I wouldn't worry about it.

I am re-installing the equipment. I think non-LCDI corded units would be grandfathered as they didn't exist and weren't required at the time of manufacture, but the breakers and receptacles are another matter. Bottom line is liability. Breakers and receptacles are already there.

 

[growler]

Changing the breakers is not really viable as 9 and 12k BTU units use 20A breakers, and they are mixed in with the 7k/15A units. Any time a change was made, the breaker would have to be changed too. Plus you can't put a 20A receptacle on a 15A circuit. Cheaper than buying new units tho. What a mess...

It is a mess but it's not your mess. They just need to figure out what size units they want to use and order that size. If they need 12K BTU units then why would they install smaller units?

For some reason this is a common problem at hotels and motels. What good would changing the receptacles do?

I know of a motel where they can't make up their mind to use either 120V or 240V counter top units in the kitchen area. It's about half and half and that's confuseing to maint. staff when they change them out.

 

[JFletcher]

It is a mess but it's not your mess. They just need to figure out what size units they want to use and order that size. If they need 12K BTU units then why would they install smaller units?

For some reason this is a common problem at hotels and motels. What good would changing the receptacles do?

I know of a motel where they can't make up their mind to use either 120V or 240V counter top units in the kitchen area. It's about half and half and that's confuseing to maint. staff when they change them out.

That is the $64,000 question. Literally. Almost half of their units are 7k, and are not going to cut it in VA summers. Their reviews say so. 80 units replaced @ 800$ ea = $64k. I've priced these units, and the difference between a 7k w/electric heat and a 12k w/reversing valve and electric heat is maybe $90; 10% or so.

Changing the breakers and receptacles would make it NEC compliant for the units they have. And limit them to undersized 7k units from there on out. Quite frankly I wasn't aware that such beasts existed before this project.

I guess I'm more than a bit apprehensive about informing the owner he's gonna need the better part of six figures to bring this place up to date just on PTACs, let alone the other building AC units which are in horrible shape/not up to par as well.

 

[drcampbell]

... If they need 12K BTU units then why would they install smaller units? ...

Don't assume that one size fits all. Suites need more capacity than rooms, west-facing rooms need more capacity than rooms facing north, south or east, and you can't just install the bigger units in every room without sacrificing humidity performance.

 

[gadfly56]

Don't assume that one size fits all. Suites need more capacity than rooms, west-facing rooms need more capacity than rooms facing north, south or east, and you can't just install the bigger units in every room without sacrificing humidity performance.

OK, I'll bite; how does installing a larger unit for a given space negatively affect humidity removal?

 

[growler]

Don't assume that one size fits all. Suites need more capacity than rooms, west-facing rooms need more capacity than rooms facing north, south or east, and you can't just install the bigger units in every room without sacrificing humidity performance.

I didn't say that one size fits all. If a room or suite needs a 12K unit then why would they ever install a 7K unit.

Mr. Fletcher thinks that they install whatever unit is available. It just so happen I know this is correct because I have seen it done many times.

My guess is that they all had the 12K units originally but someone ( management type) thought they would save some money because the smaller units were cheaper.

I installed some halogen lights at a motel for the front parking area. I told them upfront that this was a big mistake (but they were cheap, furnished by them). The lamps don't have a very long life and it cost more to maintain them than they are worth. I have charged thousands of dollars over the years to change those lamps and I'm pretty sure that someone is still makeing money off them.

 

[JFletcher]

OK, I'll bite; how does installing a larger unit for a given space negatively affect humidity removal?

They short cycle. or can. so humidity doesnt get removed as well.

growler is correct, they installed w/e they could get (usually from the owner's better/bigger properties), evidenced by the over 20 different models of PTAC at this place (that's NOT counting different BTU units of the same model or all the various mongrel remanufactured units either). There could be a 7k model in a suite, or long room, and I've even seen one 15k model, in the back dorm building, which is where I would put the units that are lesser or not as pretty, or loud, etc.

 

[kwired]

My $.02, if they have a 6-15 cord cap factory installed, it is suitable for use on any legally wired 6-15 or 6-20 receptacle.

No different then all those 5-15 cord caps out there that are inserted into 5-20 receptacles.

 

[JFletcher]

I didn't say that one size fits all. If a room or suite needs a 12K unit then why would they ever install a 7K unit.

Mr. Fletcher thinks that they install whatever unit is available. It just so happen I know this is correct because I have seen it done many times.

My guess is that they all had the 12K units originally but someone ( management type) thought they would save some money because the smaller units were cheaper.

I installed some halogen lights at a motel for the front parking area. I told them upfront that this was a big mistake (but they were cheap, furnished by them). The lamps don't have a very long life and it cost more to maintain them than they are worth. I have charged thousands of dollars over the years to change those lamps and I'm pretty sure that someone is still makeing money off them.

I speak for every former maintenance guy when I say we hate those things. You're right, lamp life is abysmal. and then there's the fact the gaskets, glass, and sockets disintegrate from the high heat. and the bright spot and burned fingers when you drop a new bulb into an energized fixture. I think the only use for them is when you need a temporary light and heat source (like painting a new house in January) and only want to carry one tool.

 

[JFletcher]

My $.02, if they have a 6-15 cord cap factory installed, it is suitable for use on any legally wired 6-15 or 6-20 receptacle.

No different then all those 5-15 cord caps out there that are inserted into 5-20 receptacles.

Yes but those appliances dont have "MOCP 15A" on them. and if I change the 20A breaker to the correct 15A breakers, I can no longer have a 6-20 receptacle on that circuit.

Liability would be my concern, but not the owner's. He didn't seem to care when I told him the other half of his units were under CPSC recall for faulty power cords. :slaphead:

 

[charlie b]

ofc they are on 20A circuits. . . .

OK, I'll bite. What does "ofc" stand for? :?

 

[growler]

Been doing a lot of electrical work for a local hotel recently. I've noticed that quite a few of their PTAC units are 7k BTU, and come with 6-15 plugs, and are rated for 15A circuits. ofc they are on 20A circuits, above what the mfg requires (MCA 15A, MOCP 15A). 6-20Rs accept 6-15 plugs.

My $.02, if they have a 6-15 cord cap factory installed, it is suitable for use on any legally wired 6-15 or 6-20 receptacle.

No different then all those 5-15 cord caps out there that are inserted into 5-20 receptacles.

Kwired I would think so to except for a unit with a nameplate that requires dedicated circuit with 15 amp MOCP. Be interesting to read installation instructions.

There isn't really any safety concern but if the unit is new it could void any warranty. That's why if I installed the equipment I will follow the manufacturers instructions. I'm not going to warranty that stuff.

 

[wwhitney]

if I change the 20A breaker to the correct 15A breakers, I can no longer have a 6-20 receptacle on that circuit.

For a single receptacle on an individual branch circuit, it is allowed to have a 6-20 receptacle on a 15 amp circuit. (2011) 210.21(B)(1).

Cheers, Wayne

 

[wwhitney]

What does "ofc" stand for?

Of course.

 

[JFletcher]

Kwired I would think so to except for a unit with a nameplate that requires dedicated circuit with 15 amp MOCP. Be interesting to read installation instructions.

There isn't really any safety concern but if the unit is new it could void any warranty. That's why if I installed the equipment I will follow the manufacturers instructions. I'm not going to warranty that stuff.

There is no warranty concern, not unless GE has a 20 year warranty. I have plugged in a few that have blown up (shorted) when turned on; the FPE breakers never tripped before the wiring burned out in the unit. Maybe a 15A wouldnt make a real difference.... just want to do what is right, and afaik plugging in equipment with 15A MOPD onto a circuit with a 20A breaker is not right. How 'not right' is debatable. Almost wish I hadn't read the stickers on the units... ignorance is bliss...

While I'm at it, would the metal wall sleeves be required to have a bonding jumper to the unit? Some of these units aren't even screwed to the sleeves, just sitting in there...

 

[JFletcher]

OK, I'll bite. What does "ofc" stand for? :?

Oregon Fried Chicken. j/k (just kidding), it's as wwhitney wrote. and ty for the reply as well, tho I dont think the 20A receptacle on the 15A breaker is kosher as the electric heat draws more than 12A continuous.... wouldn't that require the 20A receptacle? something is amiss there...