5 ton AC

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juz73

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What are the electrical specs on a 5 ton AC?
Is there a table in the N.E.C that might help me convert to Amps, and explain d:confused, disconnect sizing, breaker sizing, conductor sizing, fuse sizing etc? :confused:
 
juz73 said:
What are the electrical specs on a 5 ton AC?
Is there a table in the N.E.C that might help me convert to Amps,
Click to expand...

No, but there are some members here that have ways of getting close enough for estimates.

As far as disconnect sizing, breaker sizing, conductor sizing, fuse sizing etc you will have to see the units specifications or label, no way around that.
 
5 ton AC

Some people say ,convert to BTUH ,then to KW then divide by COP which may be 2 to 3 (to be obtained from manufacturer). The result will give you rough estimation of Elect power consumed. But I am not sure. See if someone can confirm this guideline.

gk
 
Rule of thumb for single phase is 10 amps per ton. For an example of a 4 ton calculation, click here.

As the others have said, the name plate tells you what you need to know. Install your wire sized for the minimum amps and your OCP for the maximum amps.
 
1 Ton (air cond.) = 12,000 Btu/hr and 1 kW = 3,412 Btu/hr
so you can get: 1 Ton (air cond.) = 12,000 Btu/hr / (1 kW / 3,412 Btu/hr) = 3.52 kW

If you have the EER (Btu/hr-watt): kW/ton = 12 / EER
 
TH's way:

1.25 HP per ton for 1/2-5 ton capacity
1.1 HP per ton for 5-50 ton capacity
1.0 HP per ton for capacity above 50 tons
 
HP-capacity

HP-capacity

brantmacga said:
TH's way:

1.25 HP per ton for 1/2-5 ton capacity
1.1 HP per ton for 5-50 ton capacity
1.0 HP per ton for capacity above 50 tons
Click to expand...

Does this apply to different types of compressors and their efficiencies...such as scrolled vs. piston? Just curious. rbj
 
gndrod said:
Does this apply to different types of compressors and their efficiencies...such as scrolled vs. piston? Just curious. rbj
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:D it doesn't say. that's all the info given. I haven't used that table before; i've always been able to get the nameplate specs ahead of time. I'm sure you can e-mail tom and ask him.
 
TM

TM

brantmacga said:
:D it doesn't say. that's all the info given. I haven't used that table before; i've always been able to get the nameplate specs ahead of time. I'm sure you can e-mail tom and ask him.
Click to expand...

Thanks Brantmacga,
Which book of his is the chart used?
 
juz73 said:
What are the electrical specs on a 5 ton AC?
Is there a table in the N.E.C that might help me convert to Amps, and explain d:confused, disconnect sizing, breaker sizing, conductor sizing, fuse sizing etc? :confused:
Click to expand...

the name plate has min circuit ampacity, it also lists the max ocpd rating,

is it gas or electric heat?

3 ph or 1 ph?

1.25 hp per ton

6.25 x 746 = 4.662 kw

4662/240 = 19.4a @ 240 1 ph

4662/830 = 5.6 a @ 480 3 ph
 
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gndrod said:
Thanks Brantmacga,
Which book of his is the chart used?
Click to expand...

I'm almost positive I got that out of his "Reminders for the Electrician" book. It came in an '05 NEC combo set w/ his keyword index and one other book, the title I can't remember.
 
I was taught 400 sq ft per ton 5 tons 2000 sq ft .
I am thinking 2 stories with 2 -240v 20a condensing units and 2 120v 20 a air handlers with associated lighting condensate pump outlets and general maintenance outlets both outside and attic/basement.
Low voltage connection to condensers and associated thermostat wiring.
Oh btw who is purchasing the t-stats where are they going and do they have to tie into the heating system.
I am thinking about 1600$ right now,(tstats provided by others) But that is just what I am thinking.
 
brantmacga said:
I'm almost positive I got that out of his "Reminders for the Electrician" book. It came in an '05 NEC combo set w/ his keyword index and one other book, the title I can't remember.
Click to expand...
this was out of tom henry's "reminders" but it is impossible to size heat pump/ac unit exactly depending on make and efficiency. a trane unit might spec. mca @ 34a, mocp @ 40a, where a identical unit by york might say mca @ 30a, mocp @ 40. it will get the unit sized ball park, thats why you will usually find a newer roughed in house with oversized wire.
 
csparkrun said:
this was out of tom henry's "reminders" but it is impossible to size heat pump/ac unit exactly depending on make and efficiency. a trane unit might spec. mca @ 34a, mocp @ 40a, where a identical unit by york might say mca @ 30a, mocp @ 40. it will get the unit sized ball park, thats why you will usually find a newer roughed in house with oversized wire.
Click to expand...

You could feed almost every 2k ft house done here w/ 12-2 or 14-2, especially w/ the newer more efficient models. The last several 1800 ft houses I did had 20A MOCP. Another popular thing on larger houses lately has been to use two or three 2 or 2.5 ton units. I rarely see zone controls anymore.
 
brantmacga said:
You could feed almost every 2k ft house done here w/ 12-2 or 14-2, especially w/ the newer more efficient models. The last several 1800 ft houses I did had 20A MOCP. Another popular thing on larger houses lately has been to use two or three 2 or 2.5 ton units. I rarely see zone controls anymore.
Click to expand...
At the risk of repeating myself 12-2-2
 
quogueelectric said:
I was taught 400 sq ft per ton 5 tons 2000 sq ft .
Click to expand...
There are a lot of factors to consider when sizing a A/C system. Climate zone, type of wall and attic insulation, roof color, window quality and quantity, size of eve, etc.

The most common way is the finger method. When setting in your truck at the curb, hold up your hand in front of your face. Count how many of your fingers that it takes to cover up the house from your view. A/C system would be 1 finger per ton. :grin:
 
Minuteman said:
There are a lot of factors to consider when sizing a A/C system. Climate zone, type of wall and attic insulation, roof color, window quality and quantity, size of eve, etc.

The most common way is the finger method. When setting in your truck at the curb, hold up your hand in front of your face. Count how many of your fingers that it takes to cover up the house from your view. A/C system would be 1 finger per ton. :grin:
Click to expand...
Does the thumb count as a finger? Mine is 1.3 pinkies.:D
 
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