Circuit Wiring Question

Reply

  #1  
Old 03-20-07, 09:31 AM
Member
Thread Starter
Join Date: Jan 2005
Location: USA
Posts: 119
Received 0 Votes on 0 Posts
Circuit Wiring Question

I am having a new heat pump and air handler installed for the upstairs of my house and have a wiring question. My installer said I need a 30 amp circuit for the HP and 60 amp for the air handler. My question is what type of 30 amp breaker should I use for the HP, single or double pole, and if double pole, do I connect the neutral to the neutral bar in panel box or to the other screw on the double pole breaker?
 
Sponsored Links
  #2  
Old 03-20-07, 09:40 AM
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Received 42 Votes on 40 Posts
> what type of 30 amp breaker should I use for the HP, single or double pole

You need double pole (240V) breakers for both the heat pump and the air handler.

> do I connect the neutral to the neutral bar in panel box or to the other
> screw on the double pole breaker?

There is no neutral in a 240V circuit; you have two hot wires and a ground. You may use NM "Romex" cable for the circuit and color in the last few inches of the white wire with a red sharpie marker to re-identify the wire as a hot. Each hot wire (black & red) connects to a terminal on the DP breaker, and the ground connects to the ground bus.
 
  #3  
Old 03-20-07, 09:43 AM
Member
Thread Starter
Join Date: Jan 2005
Location: USA
Posts: 119
Received 0 Votes on 0 Posts
That's pretty much what I was thinking, but wanted to make sure. Thanks.
 
  #4  
Old 03-20-07, 10:15 AM
Banned. Rule And/Or Policy Violation
Join Date: Feb 2006
Location: North of Boston, MA.
Posts: 2,113
Received 0 Votes on 0 Posts
Curious, Why is the air handler a 60 amp? Is it huge or is there additional heating in it? Heat pumps are usualy the bigger draw.
 
  #5  
Old 03-20-07, 02:04 PM
Member
Join Date: Mar 2007
Posts: 76
Received 0 Votes on 0 Posts
heat pumps

Heat pump air handlers usually have heat strips that provide several functions:

1. The hp is the first stage of heat, the heat strips are the second stage of heat [2 stage thermostat]

2. The heat strips are energized when the hp goes into a defrost cycle during the heating mode to prevent cool air from being blown into the house. The defrost cycle actually reverses the hp operation from heating mode to cooling mode which is why the heat strips need to come on during defrost

3. The heat strips provide an emergency heat function. If the hp is inoperative for some reason the heat strips can be used as a stand alone to provide heat. The thermostat has an emergency heat switch, which when utilized, reconfigures the circuitry to shunt the hp out of the loop and places the heat strips under the control of the first stage portion of the thermostat.

Air source heat pumps have some pretty complicated circuitry.
 

Last edited by helpingsis; 03-20-07 at 02:08 PM. Reason: correct some spelling
  #6  
Old 03-20-07, 02:27 PM
Banned. Rule And/Or Policy Violation
Join Date: Feb 2006
Location: North of Boston, MA.
Posts: 2,113
Received 0 Votes on 0 Posts
Thank you

Now I see. I have not dealt with heat pumps too much. I understood their basic functions but not to this extent.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: