Double-Tapped AC?

[svetz]

Found the electrical heater element label (under the box where the elements go), RXBH1724C07J, a 5.4 / 7.2 kW heater which from the table should have a maximum OCP of 45 amps. Really impressive how close you were with the handwavium @Supervstech !

So, 25 amps for the condenser and 45 for the air-handler... guess it should have been double-tapped at 70 amps... what were they thinking! ?

So... how to pick compatible circuit breakers.... amazing how many vendors have e82615.

No label on the load center I could see. Pulled a breaker so I could see the "side" label...the model for style e82615 is a Murray MP120. Interestingly it says in big letters "Use only in listed Enclosures Siemens Industry, Inc.". So, must have been from after Siemens bought them.

So two AFCI & GFCI breakers to replace the two kitchen breakers (bathrooms already have GFCI).
25 amp for the condenser
45 amp for the air handler

I also need a handful of GFCI outlets...anyone know a solid brand name?

 

[Supervstech]

Wow, the max ocp is 25, and it has #10 copper feeding it?
what is the minimum Ampacity?

 

[svetz]

Wow, the max ocp is 25, and it has #10 copper feeding it? what is the minimum Ampacity? Probably reused the wiring from the prior unit. The model number is 13ajn30a01, so 13 SEER and model 30, so from the guide the min/max is 25/25...probably says on the label too... let me see if I still have the photo of that...

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[Supervstech]

Probably reused the wiring from the prior unit. The model number is 13ajn30a01, so 13 SEER and model 30, so from the guide the min/max is 25/25...probably says on the label too... let me see if I still have the photo of that...

View attachment 26022​

View attachment 26023​

Minimum circuit ampacity is 17 amps, so 14 wouldn’t be enough, 12 would have. 10, likely was just what was already there. Make sure the breaker isn’t bigger than 25 amps.

 

[svetz]

Make sure the breaker isn’t bigger than 25 amps.

You betcha! I'll have it off that double-tapped 60 amp breaker as soon as the new one arrives! Thanks again for all your help!

Did I mention the previous owner was a fireman? Now, if I could just get those construction companies to come out ang give me an estimate for the attic I could get the roof started. Have to run now to meet with the tree trimmers... hopefully no houses will be crushed by the enormous branches being removed.

 

[Hedges]

Minimum circuit ampacity is 17 amps, so 14 wouldn’t be enough, 12 would have. 10, likely was just what was already there. Make sure the breaker isn’t bigger than 25 amps.

The fatter wire is good for less voltage drop starting.
Label says 25A max breaker, but operating current 12.8A
Smaller 20A breaker would trip sooner in the case it tries to start back up after a brief power interruption, before pressure has bled off.
Stalled out, the motor windings will get hot, and so will the breaker. Tripping sooner means insulation gets less baked.

Label claims same 12.8A whether 208 or 230V, but of course would be slightly lower on 230V.
A 15A breaker would be slightly below 1.25x 12.8A, but might be enough above actual operating current.
Mine was wired with 15A, and has tripped occasionally. It did that recently during a hot spell. I loosened up the vines which had grown over the condenser, and that may or may not have been why it didn't trip a second time.

Ideally we'd have a breaker that allowed 60A for 5 seconds, then tripped. Breakers have an instant magnetic trip and then a thermal curve taking seconds to minutes. Breakers and fuses do protect motors. So do thermal limit switches physically mounted on motors, and 3-phase motor starters which are thermal breakers with changeable elements.

 

[svetz]

...I loosened up the vines which had grown over the condenser, ... may or may not have been why it didn't trip a second time.

Now that's funny!

So, remember I said the condenser wasn't bolted down and vibrates? Took the hammer drill, bits, and tapcons out today to rectify that.

Turns out it's on a pad of some sort and doesn't have any feet to bolt down. Can't tell if that's one pad or perhaps 4 foam feet?

No vines on mine, but I'm thinking "hmmm, rust... I can treat that with phosphoric acid...not like @Supervstech will find out...." ? That hole looks suspiciously like a place to bolt the unit down.

The installation guide has three sections on this: "Proper installation", "Unit Mounting", and "Factory-preferred tie-down"; none of which are helpful. One of the guidelines says a "base pad" elevates 3/4" and googling base pad shows a single pad and the corner of the pad in the photo above does look like it. Didn't see anything in the installation guide on that... guess I need to do some research... Oh joy... it looks like a lot of people don't bolt them down because doing so is bad for them (ref). In our hurricane prone area the building code demands it and you can't get insurance without it. They make something call condenser tie downs, which look to be expensive and cheaply made L brackets. Seems like a flexible tie down would be best? Doesn't look like anyone makes those. Maybe they look cheap because they flex? Who knew this engineering would be so tough?

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Update: Florida approval on a type of tie-down for grade and roof: https://floridabuilding.org/upload/PR_Instl_Docs/FL14239_R3_II_Dwg.pdf

 

[Supervstech]

Those pads are osb rubber isolation noise spacers. I’ve used them, a solid rubber waffle type, a cork separated rubber pad type, and a foam separated rubber pad type.
Also there are riser feet available. We are inland, and extremely rarely get hurricane winds. On the coast, in sc, there aren’t any tie down rules.
It’s funny to me to tie them down to the plastic pad... because the pad is going to float away... unless the pad itself is tied down.

either way, if it is a heat pump, it needs to be spaced up off the pad for winter ice melt drainage.

 

[Supervstech]

The fatter wire is good for less voltage drop starting.
Label says 25A max breaker, but operating current 12.8A
Smaller 20A breaker would trip sooner in the case it tries to start back up after a brief power interruption, before pressure has bled off.
Stalled out, the motor windings will get hot, and so will the breaker. Tripping sooner means insulation gets less baked.

Label claims same 12.8A whether 208 or 230V, but of course would be slightly lower on 230V.
A 15A breaker would be slightly below 1.25x 12.8A, but might be enough above actual operating current.
Mine was wired with 15A, and has tripped occasionally. It did that recently during a hot spell. I loosened up the vines which had grown over the condenser, and that may or may not have been why it didn't trip a second time.

Ideally we'd have a breaker that allowed 60A for 5 seconds, then tripped. Breakers have an instant magnetic trip and then a thermal curve taking seconds to minutes. Breakers and fuses do protect motors. So do thermal limit switches physically mounted on motors, and 3-phase motor starters which are thermal breakers with changeable elements.

12.8 FLA IS JUST FOR THE COMPRESSOR... remember, there is a fan motor, and capacitors, circuit boards, relays etc... the minimum circuit ampacity is on the tag at 17/17 so, #14 would fail inspection. (All residential circuits follow the 60C table) a 20A breaker would pass, but it may give nuisance trips. 25 is the MAX breaker, and for some reason, Rheem uses a minimum breaker spec also... which is 20 on his unit.

 

[svetz]

By now you're wondering why I didn't just hire someone out to do this. Since Halloween is coming up I'll tell you my horror stories...

The problem is finding professionals in the keys. Oh, there are a dozen businesses in the area... and I bet the owners are probably good... but I haven't found anyone that is consistently competent. True story...my sister-in-law called her HVAC guys and said there was water under the air handler. The guy came out and said the condensate line was clogged and charged her to blow it out and installed a cut-off sensor.

She called me because two days later, it's still leaking. He had installed the new sensor in series to the perfectly working old sensor that was already there and did flush the lines. He even wired the new sensor in series so either would trip. In my one minute inspection I see the pan is cracked - it wasn't even trying to hide. I'm pretty sure they cracked the pan the month prior after charging her $1k to take out and clean the coils. I never saw the coils, so can't comment on if they needed to be cut out and cleaned. Anyway, since replacing the pan would have cost a lot I dried out the pan and filled the crack with silicone caulk and told her to keep an eye on it. It's been a couple of months with no problems, knock on wood.

I'm sure it's more a case of the individual that comes to your door. For example, I hired an electrical company to do some wiring for me. Two guys were in the crew. One guy did beautiful work, even my OCDness approved of it. The other guy's work looked good too on the surface, but I opened up some of the runs he did a month later (trying to isolate an electrical issue) and was horrified by what I found (bare live wires). The live wires weren't even the problem, it was a wire that hadn't been screwed down to a receptacle that was in advance of the circuit.

 

[svetz]

Those pads are osb rubber isolation noise spacers.

They're working well, they're pretty noisy.

... it needs to be spaced up off the pad for winter ice melt drainage....

ROFL! For ice melt to be an issue here the freezer would first have to break. ?

This condenser is grandfathered in, but the next one will have to be mounted on the side of the house about 7' up to get over the BFE+1.
The codes change (after Wilma I think) so that all electrical has to be above the "basic flood elevation". I think that's when the condensers had to be tied down too (apparently when a tornado rips them off your roof the refrigerant lines cut through the roof pretty easily as they take the air handler off to Oz).

 

[svetz]

I love the internet... So, for my area (175 mph, exposure D) looks like this applies:



Just over 6 sqft, so get to round up to 9, at Grade, so tie-down C2.

4" concrete, so 2.25" 5/16 tapcons, and 8 tie downs.


Which of course means the earlier photo was of a unit installed completely wrong.

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So, now I just need to find Dade-County HVHZ approved condenser 1" tie down straps....

 

[Supervstech]

By now you're wondering why I didn't just hire someone out to do this. Since Halloween is coming up I'll tell you my horror stories...

The problem is finding professionals in the keys. Oh, there are a dozen businesses in the area... and I bet the owners are probably good... but I haven't found anyone that is consistently competent. True story...my sister-in-law called her HVAC guys and said there was water under the air handler. The guy came out and said the condensate line was clogged and charged her to blow it out and installed a cut-off sensor.

She called me because two days later, it's still leaking. He had installed the new sensor in series to the perfectly working old sensor that was already there and did flush the lines. He even wired the new sensor in series so either would trip. In my one minute inspection I see the pan is cracked - it wasn't even trying to hide. I'm pretty sure they cracked the pan the month prior after charging her $1k to take out and clean the coils. I never saw the coils, so can't comment on if they needed to be cut out and cleaned. Anyway, since replacing the pan would have cost a lot I dried out the pan and filled the crack with silicone caulk and told her to keep an eye on it. It's been a couple of months with no problems, knock on wood.

I'm sure it's more a case of the individual that comes to your door. For example, I hired an electrical company to do some wiring for me. Two guys were in the crew. One guy did beautiful work, even my OCDness approved of it. The other guy's work looked good too on the surface, but I opened up some of the runs he did a month later (trying to isolate an electrical issue) and was horrified by what I found (bare live wires). The live wires weren't even the problem, it was a wire that hadn't been screwed down to a receptacle that was in advance of the circuit.

Yeah, when my aunt was alive, in Lakeland, we routinely had to trek down there to give competent service to her place...
I feel for you getting quality techs in your area.

another site I moderate is HVAC-TALK.com, they have a free member contractor locator there that may help you locate a good tech.
Facebook and other community recommendations are usually a good bet also.

 

[Supervstech]

They're working well, they're pretty noisy.


ROFL! For ice melt to be an issue here the freezer would first have to break. ?

This condenser is grandfathered in, but the next one will have to be mounted on the side of the house about 7' up to get over the BFE+1.
The codes change (after Wilma I think) so that all electrical has to be above the "basic flood elevation". I think that's when the condensers had to be tied down too (apparently when a tornado rips them off your roof the refrigerant lines cut through the roof pretty easily as they take the air handler off to Oz).

What low temps do you see there in the winter months? 60? I remember several days in the 30s in Orlando in 97...

even if not ice melting, in heating mode the condenser flows a lot of moisture off the outside coils, so drainage is important for them.

 

[svetz]

What low temps do you see there in the winter months? 60? I remember several days in the 30s in Orlando in 97...

even if not ice melting, in heating mode the condenser flows a lot of moisture off the outside coils, so drainage is important for them.

I've only been here a few years, winters are pretty much perfect weather days (it's also the tourist season). Summer is pretty much the perfect season for HVAC professionals.

We're an island surrounded by water that varies from 88°F down to 72°F, so that buffers us a lot. That said, I've seen it as low as 49°F. Google says January 13, 1981 and December 24, 1989 were the last two coldest lows on record at 35°F. Of course, that's pre-dawn low... it warms up. What's funny (having moved from Colorado) is to see natives in fur parkas when the temperature drops to 60°F (last year I was getting odd looks walking around in a T-shirt and shorts). I think there was even a day where we turned the heat on overnight.

Cold days like that are EXTREMELY HAZARDOUS.... something the rest of the nation doesn't have to deal with: https://www.bbc.co.uk/newsround/51203724#:~:text=The National Weather Service (NWS,the warmth of the Sun.

 

[Supervstech]

I've only been here a few years, winters are pretty much perfect weather days (it's also the tourist season). Summer is pretty much the perfect season for HVAC professionals.

We're an island surrounded by water that varies from 88°F down to 72°F, so that buffers us a lot. That said, I've seen it as low as 49°F. Google says January 13, 1981 and December 24, 1989 were the last two coldest lows on record at 35°F. Of course, that's pre-dawn low... it warms up. What's funny (having moved from Colorado) is to see natives in fur parkas when the temperature drops to 60°F (last year I was getting odd looks walking around in a T-shirt and shorts). I think there was even a day where we turned the heat on overnight.

Cold days like that are EXTREMELY HAZARDOUS.... something the rest of the nation doesn't have to deal with: https://www.bbc.co.uk/newsround/51203724#:~:text=The National Weather Service (NWS,the warmth of the Sun.

Yup, I grew up in Eastern Washington gt9n, and SOUTH FRIGGIN DAKOTA...
Those are some brutal winters...

 

[svetz]

What do you know... the brackets aren't all that expensive... https://www.bakerdist.com/bmp-bmtd04s-4in-x-1in-tie-down-clips-with-screws--7907ba9

 

[Supervstech]

What do you know... the brackets aren't all that expensive... https://www.bakerdist.com/bmp-bmtd04s-4in-x-1in-tie-down-clips-with-screws--7907ba9

I have an account at baker, I can check if my price is better. I should be able to order it, and have you pick it up at your store.

 

[Supervstech]

Ouch... nearest store to you is in del ray beach... a bit of a drive.

 

[svetz]

Ouch... nearest store to you is in del ray beach... a bit of a drive.

The first store (Miami) I looked didn't have any in stock... had to order from Naples... $12 shipping... no driving required. I'm so spoiled with Prime.
Thanks for the offer! But I've already ordered them.