Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-14-2011, 01:08 AM   #16
Newbie
 
Join Date: Oct 2011
Location: Queensland, Australia.
Posts: 8
Share |
Default

Contactor for pool pump timer


In Aus. we have active (live), a neutral to create a circuit after the current has gone through a device to give it energy/power and an earth for protection. The neutral will carry less current as it has been used up mainly by whatever device(s) are on the circuit. Back at the switchboard all the neutrals for all the circuits (unless they are safety switched) connect to the same link (which also connects to the main earth for added protection), which then connects to the mains neutral that eventually goes back to the regional generation station. Is that what you mean by phase to neutral?
Additionally to clarify, if you touched a live active to a neutral (without the active's current/voltage/power going through a device first) it would "short" or deactivate the circuit making a sharp explosive sound or "bang"!


Last edited by Bushido; 10-14-2011 at 01:32 AM.
Bushido is offline   Reply With Quote
Old 10-14-2011, 05:19 AM   #17
Sparky
 
Join Date: Mar 2011
Location: Central Florida
Posts: 699
Default

Contactor for pool pump timer


here we have 2 'lives', and 1 neutral. between live and neutral we get 120v, between the two lives we get 240v.


load from timer to a1, neutral to a2, pump hot(from panel) to 1, Pump load(from contactor to pump) to 2
Techy is online now   Reply With Quote
The Following User Says Thank You to Techy For This Useful Post:
Bushido (10-14-2011)
Old 10-14-2011, 08:22 AM   #18
Electrician
 
SD515's Avatar
 
Join Date: Aug 2008
Location: Near Jackson Michigan Area
Posts: 1,450
Default

Contactor for pool pump timer


What you describe is phase to neutral, and similar to what we use. On a branch circuit you should read 240V phase (active) to neutral, 240V phase to earth, 0V neutral to earth.

On a single circuit that’s phase to neutral, neutrals carry the same amount of current as the phase line. The current isn’t going to disappear when it goes through a device. What goes in must come out, otherwise you have a short and it’s going someplace it’s not intended to.

The single circuit diagram posted earlier will work if the conductors are sized appropriately to carry the amount of current the circuit is to use. Most of the current will be used by the pump motor. The listing of the contactor states the coil will use 1.9W/3VA, or about 10-12 milliamps @240V. Unknown what the timer will use, but generally they don’t use much either. I’ll post another diagram showing a 2 circuit set-up as an alternate.
__________________
Kyle

Just because you can, doesn't always mean you should
SD515 is offline   Reply With Quote
Old 10-14-2011, 08:44 AM   #19
Electrician
 
SD515's Avatar
 
Join Date: Aug 2008
Location: Near Jackson Michigan Area
Posts: 1,450
Default

Contactor for pool pump timer


2 circuit wiring diagram. Colors used for reference only.
Attached Thumbnails
Contactor for pool pump timer-timer-contactor-alternate.png  
__________________
Kyle

Just because you can, doesn't always mean you should

Last edited by SD515; 10-14-2011 at 08:57 AM.
SD515 is offline   Reply With Quote
The Following User Says Thank You to SD515 For This Useful Post:
Bushido (10-14-2011)
Old 10-14-2011, 06:15 PM   #20
Newbie
 
Join Date: Oct 2011
Location: Queensland, Australia.
Posts: 8
Default

Contactor for pool pump timer


OK I think we're on the same playing field now. Good to learn -thanks. I'll go back next week and install it.
A few more questions though for future reference;
I suppose this same system can be applied to lighting circuits or other motor circuits that are controlled just by a circuit breaker and no timer?
Is one purpose of the contactor to limit/reduce higher starting currents?
Bushido is offline   Reply With Quote
Old 10-14-2011, 10:25 PM   #21
Electrician
 
SD515's Avatar
 
Join Date: Aug 2008
Location: Near Jackson Michigan Area
Posts: 1,450
Default

Contactor for pool pump timer


No, the purpose of using a contactor is not to limit starting currents. That can be done by other means, like a soft-start kit, variable frequency drive, etc.

Contactors act as a switch. Some common examples of their use is when the amperage of the load exceeds the amperage rating of a/the switch, when multiple circuits are to be switched simultaneously, or when multiple phases of the same circuit are to be switched simultaneously (ie. a 3-phase circuit). Most contactors contacts are normally open, and close when the coil is energized. Contactors can be used to control most any equipment (lights, motors, etc.) as long as the ratings are adequate.

Contactors need something turn them on, to energize the coil so it will close (or open the contacts, depending on the construction of the contacts). A timer can be used, as can a switch, a breaker, or a photocell for example. When the coil is energized, the solenoid pulls the contacts in, and whatever power is hooked up to the contacts is now allowed to flow through to the load. De-energize the coil and the power is cut off from the load, and the equipment stops. Just like a switch does.

Example: Photocells are commonly used to control parking lot lights. Instead of running all the power that the lights need through the photocell, which may be more than the photocell can handle, or is of multiple circuits, the lighting power is run through the contactor(s), and the contactor is controlled by the photocell. When it gets dark, the photocell send power to the coil, which makes the contactor close and the lights come on. When it gets light enough, the photocell stops the flow to the coil, it de-energizes, the contacts open, and the lights shut off.

Maybe the customer wants a timer instead of the photocell. No problem, replace the photocell with a timer. Maybe they want a wall switch. No problem, install a wall switch instead. The controlling device will have little power going through it…just the amperage the coil needs when energized. A couple years ago I worked on a retail store that had about 15 lighting circuits, controlled by three 3-way circuits, using 5 contactors. Lots of power needed to run the lights, yet hardly anything going through the switches themselves. The contactors carry the bulk of the load.

Making sense?
__________________
Kyle

Just because you can, doesn't always mean you should
SD515 is offline   Reply With Quote
The Following User Says Thank You to SD515 For This Useful Post:
Bushido (10-15-2011)
Old 10-18-2011, 01:28 PM   #22
Newbie
 
Join Date: Oct 2011
Posts: 1
Default

Contactor for pool pump timer


Thanks for the information...

Pool Parts

henrystrange is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Intermittent submersible pump fault esquilax Electrical 5 09-30-2011 03:56 AM
Well Pump Problems dannyjoe Plumbing 6 10-01-2009 06:10 PM
Sump Pump Questions henlij Plumbing 19 08-12-2009 07:50 PM
pool timer/ pool pump hook-up bubbahines Electrical 4 05-29-2009 05:03 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.