Confused about breaker size - round up or round down?

C

CanadaCanuck

Member
Location
BC
Occupation
GC
Electric air handler with auxiliary heat strip being installed in Canada.
Motor FLA 2.1 amps
Heat strip (8kW) 33.3 amps
The unit has a built-in double pole 45 amp breaker which serves as the termination point for the supply line
The manual states that the maximum amperage of the breaker in the supply panel is 45 amps (but this is not printed on the nameplate)

They do not make a Schneider Homeline 45 amp breaker in Canada.

If I round up to 50 amps, then I am ignoring the instructions in the equipment manual.
If I found down to 40 amps, then I am running a breaker at 88.5% continuous load which exceeds the 80% continuous loading.

Which way do I go?

From a safety and logic standpoint, I like the idea of using a 50 amp breaker and 6/2 wire. I'm fully protecting the wire, shouldn't get nuisance trips, and I'm not exceeding 80% continuous loading on my breaker. The equipment itself is protected with its internal 45 amp breaker. However, I get uneasy about ignoring the clealry stated requirement in the manual.

The other option is to run a 50 amp breaker in the panel to a disconnect with a 45 amp breaker but that seems silly.
 
infinity said:
What is the MCA on the nameplate? Can you post a photo?

Welcome to the Forum.
Click to expand...
I've been going off the installation manual and racking my head at how to make the numbers work. To respond to your post I went to take a picture of the nameplate and it has different information. It says that I can use a 50 amp breaker. Problem solved. Thank you!
 
Welcome to the forum.

I would go with your 50a plan.

As Rob asked, what are the MCA and the MOC?
 
CanadaCanuck said:
I've been going off the installation manual and racking my head at how to make the numbers work. To respond to your post I went to take a picture of the nameplate and it has different information. It says that I can use a 50 amp breaker. Problem solved. Thank you!
Click to expand...
It happens. Instruction manuals for equipment often contains incorrect information.
 
I would call the Manufacturer's technical Support and explain the scenario, always the manufacturer is the best judge for protection requirement of their own device, I would get them to send me an email and keep it as a record just in case to present it to Electrical inspector, Client or their representative
 
Glad you figured it out.
For some reason lots of newer HVAC stuff is specifying these X5 sized breakers so I have run into this also and they do make a Homeline two pole breakers in the X5 amp sizes 15, 25, 35 and 45 amp Homeline breakers the part numbers are HOM215 , HOM225, HOM235, HOM245 there is no difference between the US and Canadian versions.
I have run into counter sales people whom are not aware of this and just say they don't make them.
I think in Canada the only thing different with Schneider is you can get *more* breakers options and brands not less.
1735879597395.png
 
This situation is resolved, but it is not uncommon today. When we are also dealing with fully rated breakers, we run in to the situation where the x5 breakers aren't made. The only solution is to use a fused disconnect.
 
Strathead said:
This situation is resolved, but it is not uncommon today. When we are also dealing with fully rated breakers, we run in to the situation where the x5 breakers aren't made. The only solution is to use a fused disconnect.
Click to expand...
Are you saying that some manufacturers aren't making circuit breakers in the standard sizes (15, 25, 35, 45) straight out of NEC Table 240.6(A)?
 
Strathead said:
This situation is resolved, but it is not uncommon today. When we are also dealing with fully rated breakers, we run in to the situation where the x5 breakers aren't made. The only solution is to use a fused disconnect.
Click to expand...
When you say fully rated that makes me think were talking about different things, I was talking about typical 2-pole plug on residential/light commercial breakers that go in your typical loadcenter that you'd need for hooking up a HVAC unit like a heatpump or minisplit.
Not too long ago I needed several 35A Square D homeline breakers and a counter guy said they did not make them, a few annoying phone calls proved they did.
 
Strathead said:
This situation is resolved, but it is not uncommon today. When we are also dealing with fully rated breakers, we run in to the situation where the x5 breakers aren't made. The only solution is to use a fused disconnect.
Click to expand...

What exactly do you mean by "fully rated"? As in not slash rated? Or the higher AIC breakers such as 22 or 65k?
 
For residential HVAC I rarely see the need for over the standard 10kAIC.
I have seen a old 'split bus panel' where you need 22 KAIC for the 6 mains in the main section.
Siemens at least makes a 22k 45A it is a Q245H:
I am pretty sure Eaton BR also makes them.
Siemens takes the cake though they even make a 2-pole GFCI breakers 45A GFCI breaker:
1736185057848.png
 
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