Electrical Wiring in the Home/Heat Pump Timer


I have a 220v pool heat pump. It draws 25 amps each side.  It has a two pole contactor. I would like to use a timer that I already have but it only has a SPST 40A switch. I think that will be O.K. but I just want to confirm.
Thanks, Don

Robert Wilber
Philadelphia Licensed Electrician
Philadelphia License # 3516 - 16765
Robert Wilber
Philadelphia Electrician
Philadelphia License # 3516 - 16765
Electricity is dangerous!
You can be injured or killed!
Improper installations can cause fire, injury and death!
Are you qualified to do this work?
National Electrical Code definition, NFPA 70 2008 Article 100: Qualified Person. "One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved."
Electricity is fire in a box! Death on a leash!
Always check with the local “Authority Having Jurisdiction” for an official interpretation before making installation decisions.
In Philadelphia, it is unlawful for anyone except an individual licensed by the City of Philadelphia to install electrical equipment and wiring.
Homeowners are not allowed to install wiring.
The owner of any property wherein any such installation is discovered shall be issued a violation by the Department of Licenses and Inspections.
The limited exceptions include replacing devices and fixtures at existing outlets.
Contact the Department of Licenses and Inspections for more information.
You are more likely to be killed by 120 volts than any other voltage [120 volts creates the PERFECT fatal current through the human body's electrical resistance!]
This information is provided for the use of parties as they see fit!
I am not responsible for the application of this information by any party, including those lacking sufficient skill or knowledge to perform these steps safely and any hazard created is the SOLE responsibility of the user.
Sorry for the delay in responding

25 amps on a two-pole breaker is 25 amps. Current runs in a loop. Each side of the breaker is monitoring the same current. A 40 amp switch is adequate for a 25 amp circuit.
Remember that a single pole switch will leave the entire circuit energized at all times.
Why would you want to use such a timer in the power conductor for the heat pump?
Wouldn't it be simpler and more useful to get a programmable thermostat that would allow you to set operating times and temperature variables?
About Electrical Wiring in the Home
This site answers questions related to home electrical wiring, home wiring, general electrical help,and other electrical questions related to aleternating current (AC). You can find help on the National Electical Code, home electrical issues, wiring electrical outlets, installing lighting, electrical grounding, and general electrical help for do-it-yourself projects not require an electrician. If you do not see your home electrical wiring question answered in this area then please ask your electrical wiring question here

Electrical Wiring in the Home

All Answers

Answers by Expert:

Ask Experts


Robert Wilber


Licensed Philadelphia electrician serving Delaware, Chester, Montgomery and Philadelphia County in Pennsylvania. I install and repair residential, commercial and industrial wiring and lighting. Troubleshooting and repair of problems that stump other people is my favorite. I am willing to help people figure out why things don`t work. I understand motor controls, transformers and machine wiring. I do not teach basics to novices or do free design work.


Experience in the area I have 44 years experience in residential, commercial and industrial electrical construction and repair, 480 volts and below. This is not to be confused with one week repeated two thousand times.

44 years experience in residential, commercial and industrial electrical construction and repair

©2016 About.com. All rights reserved.