On Saturday, August 2, 2014 7:41:32 PM UTC-4, email@example.com wrote:
I made exactly the same point. The spec sheet says the rated imput wattage is
4600W. That's 19A, which also happens to be the compressor RLA. It's 41000btu,
3.7 tons. And it's 16 SEER. You couldn't sell it here period, it wouldn't
meet the min federal SEER standards. Just from practical experience, #6
makes no sense.
Clare is looking in the wrong end of the telescope. He's trying to analyze
the load. The engineers already did that and put the "min circuit ampacity 26A"
on the UL label. The load is saying, "Hook me up to a 26A or greater circuit."
On Sat, 02 Aug 2014 19:23:06 -0400, firstname.lastname@example.org wrote:
Are you simply not paying attention here. The 80% does not apply here
at all. It is already computed in the minimum circuit ampacity.
Continuous load doesn't apply to motor loads anyway since the
conductors are already sized to 125% of FLA.
On Sat, 02 Aug 2014 17:06:41 -0400, email@example.com wrote:
I just went bact to the OP's post. I quote:
"Hi, I'm the OP.
Yes, the mini split a/c system specs explicitly call for a 50amp
breaker and #6 AWG (although I shudder to think that it'll actually
use that much, with a 16 SEER)."
What does the code say about over-protecting a cable?
The cable is protected by a 50 amp breaker. Going by "general code"
you cannot run an AWG10 circuit on a 50 amp circuit.
What specifics outside of the "general code" would allow the cable to
be protected with an over-rated protection device?
And yes, the air conditioner in my house is connected with stranded
flexible conductors from the house to the outside unit - run through
weatherproof flexible conduit to the "protected disconnect" - a
weatherproof single circuit circuit breaker enclosure.
The outdoor unit sits on a plarform of concrete blocks on a base of
concrete patio stones, and is not bolted down.. Been that way for over
40 years. (except the original unit sat right on the patio stones, I
raised the unit on concrete blocks to keep it out of the dirt and
leaves when I had the unit replaced.
On Saturday, August 2, 2014 8:09:08 PM UTC-4, firstname.lastname@example.org wrote:
OMG, here we go again. Gfre went through that days ago. I did
too when yesterday someone started in with the same nonsense.
The 15 amps for 14g, 20 amps for 12g, 30 amps for 10g rules
works for lights and receptacles.
It doesn't work for motor and compressor loads. You can indeed have
a 50 amp breaker on 10g wire because the overcurrent protection in
the AC load is in the AC. The breaker is there to protect against
short circuits and it needs to be 50A to handle the brief startup
The rest of the code that covers motors, HVAC compressors, etc.?
And you call that a *cord* up in Canada? Around here we call that
THWN run in liquidtight.
You see any up there that use #6?, especially a minisplit that's just
3.7 toms? If it needed that much power it would be such a pig that
it could not be sold because it wouldn't meet the min SEER standards.
That's the nutty part about this. Just from practical experience it's
obvious that #6 is a mistake.
And back to the original issue, here's another way of looking at it.
You're looking in the wrong end of the telescope. You're trying to
analyze the load, apply rules and then size the circuit. The engineers
already did that. They put "min circuit ampacity 26A on the UL label.
That means the load is saying, "Hook me up to a circuit capable of
supplying 26A or more."
On Sat, 02 Aug 2014 19:41:32 -0400, email@example.com wrote:
How many BTUs is the unit? If it is a high BTU unit, the seer could
still be pretty good with over 25 amps of current draw.
Regardless - the OP clearly stated the installation instructions
specified #6 cable and a 50 amp breaker. He also stated it requires a
"minimum ampacity" of 26 amps.
That is all we KNOW.
Do we have the manufacturer and model number of this "mythical
On Saturday, August 2, 2014 8:42:04 PM UTC-4, firstname.lastname@example.org wrote:
I think I'm starting to detect a big part of the problem here. You've now
said that with your newsreader you can't go back and view previous posts.
Now you're asking how many BTUS is the unit? I've posted that about 6 times
recently. You also haven't replied to any of my posts. So, it's obvious you've set your newsreader to ignore my replies or else you're deliberately
avoiding them and God knows what else. You're flying in the dark.
Again, that was stated in previous posts. It's not all we know, because
at least Gfre and I have pulled up the actual spec sheet. For example, you've
asked "How much current does this draw?". The spec sheet clearly says the
RLA for the compressor is 19, the fan 1, the rated power input is 4600 Watts.
Again, I've posted that many times now, but you apparently don't give a damn
so you just ignore me and make an ass of yourself.
Sea Breeze SMZ42H46ZOGX.
On Sat, 02 Aug 2014 19:44:01 -0400, email@example.com wrote:
And none of us knows enough about this "mythical beast" to know why it
is specified to be connected to a 50 amp breaker by AWG6 cable.
It's all conjecture at this point - your conjecture and mine equally
valid until more real information is provided.
On Saturday, August 2, 2014 9:15:32 PM UTC-4, Doug Miller wrote:
Plus it doesn't matter, because all of that was taken into account by
the engineers when they put "min circuit amapacity 26" on the UL label.
He's trying to analyze the load all over again, when it's been done and
the load is saying "hook me up to a 26A or better circuit".
Irrespective of what the OP may or may not have written, it's
pretty clear that you're not actually very familiar with what is,
or is not, on a UL label.
Just stop. You're only digging the hole deeper.
On Sat, 02 Aug 2014 20:44:21 -0400, firstname.lastname@example.org wrote:
He actually posted the model number and I had no problem finding the
documentation. That is where I got the minimum ampacity. It is a tad
less that 4 tons if he has the maximum number of evaporators
connected. If there are fewer, it uses less power.
On Saturday, August 2, 2014 11:31:26 PM UTC-4, email@example.com wrote:
This is unbelievable. He hasn't looked at either the spec sheet or the
pertinent data from it, which has all been posted here. In particular,
he's asking how many BTUs it is? I've posted about 6 times that it's
41000, or 3.7 tons. And that the RLA of the compressor is 19A, the fan is
1A, yet he's pretending it's normal running amps could be 26A for 3 hours?
And just from practical experience, has anyone ever seen a new 3.7 ton
AC connected with #6? As you pointed out, if it took that much power it
couldn't be sold because it wouldn't meet the min SEER standards.
That install manual has other big mistakes in
the wiring section, it calls for "4 conductor cord", when what they clearly
show connected is only the normal 2 conductors plus ground. Clare apparently
has even bought that and was arguing for connecting it with a "cord".
I think he's ignoring me. I guess it's better to remain in the dark.
On Sat, 02 Aug 2014 22:43:33 -0400, firstname.lastname@example.org wrote:
I have pointed out several times "continuous load" issue does not even
apply to motor circuits.
The 80% is an article 430/440 requirement and was engineered into the
minimum circuit ampacity specification.
Let me do a calc for you
Take a 120v 1HP motor that has a 16a FLA
The conductor needs to be sized at 125% of FLA (the inverse of 80%)
That is 20 amps. (430.22)
Table 310.16 says that can be a 14 gauge copper wire, even in the 60c
You are also allowed to increase the over current device to 250% of
FLA or 40 amps as long as the motor has overload protection (internal
or external) (430.52)
So you have a 1HP motor, on 14 gauge wire with a 40 amp breaker.
The same type of logic works in air conditioners. Since these are
complex machines with several motors and other loads, U/L requires
that there is a label with the computed values of "maximum over
current device" and "minimum circuit ampacity" from the manufacturer.
Both of those numbers are in the installation guide I found and they
specify 50a breaker and minimum ampacity of 26a. That is 10 gauge
Nothing else in that pamphlet means shit when you are sizing the
breaker and the wire.
I am even disturbed a little about the use of "cable". I suppose you
could use UF or SE if it was properly protected but the usual
installation from the disconnect to the condenser will be in sealtite
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