need to find dependable 50 amp DPDT relay.

Reply

  #1  
Old 01-12-11, 12:21 AM
NEC_HELP's Avatar
Member
Thread Starter
Join Date: Jan 2011
Location: USA
Posts: 21
need to find dependable 50 amp DPDT relay.

I need to be able to switch from one 240v load to a second 240V without being in danger of energizing the 'off' load....possible now from from human error or timer malfunction.
I need the main power source to switch back and forth Controlled by a timer, The traditional 30 amp DPDT relays are crud and the coils burn out.
I found a couple of unique product out there:
( EcoVantage Catalog: Lyght Power 50 amp /240V Relay Based )
but not sure if there is a better solution.
I heard about a type of contactor, but I have not found any specific into detailing one that can do a DPDT of 50 amps, on command..( timer
either 12/24v or 120v coil will due.)
 
Sponsored Links
  #2  
Old 01-12-11, 06:07 AM
Member
Join Date: Jun 2008
Location: VA.
Posts: 813
I would suggest a couple of mechanically held contactors with maybe even NC contacts instead of NO contacts. These would help prevent coil burn out because it's energized briefly just to switch over and then it's mechanically held. Your transfer switch would work also.
 
  #3  
Old 01-12-11, 06:16 AM
Member
Join Date: Jul 2009
Location: SE Iowa
Posts: 71
Sounds like you need a reversing contactor.
 
  #4  
Old 01-12-11, 06:47 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,383
Originally Posted by wirenut1110 View Post
I would suggest a couple of mechanically held contactors with maybe even NC contacts instead of NO contacts. These would help prevent coil burn out because it's energized briefly just to switch over and then it's mechanically held. Your transfer switch would work also.
This would work, but he'll have to use an electronic time clock capable of providing a pulse voltage and not a constant voltage that most mechanical time clocks deliver.
 
  #5  
Old 01-17-11, 10:09 PM
NEC_HELP's Avatar
Member
Thread Starter
Join Date: Jan 2011
Location: USA
Posts: 21
Yes! pointed in the correct direction!! thanks!

SO just so I am clear..a reversing contactor would do the same exact thing as a DPDT power relay?
( switch from one set of 240v current carrying conductors to another, actuated by a timer, or electronic time clock )

I have tried using several 40 amp definite purpose contactors., but one of them started to fail..buzzing loudly and not fully engaging every time.. I was never over 28 amps load.
I figured there must be a large voltage spike when the current goes through the contactor.
and yes I have been using 12v 120v digital timers, but they fail as well. (intermatic).. I would be great to advance my pool of knowledge and learn about more industrial sized devices! I'll look for tutorials on the web..or any advice would be great!

what about IEC contactors.. is this more dedicated towards my application?? ie: parking lot lighting systems.
thanks for you time and help!!
 
  #6  
Old 01-18-11, 11:31 AM
Member
Join Date: Jul 2009
Location: SE Iowa
Posts: 71
A reversing contactor is generally two separate contactors that are mechanically interlocked to keep one from turning on if the other contactor is currently energized. Normally they are used to change direction on a motor (hence the name).

How far away from the timer are you placing these relays? Is there a voltage drop that is effecting the coils causing them to burn out? Or are you using inexpensive relays that aren't meant for continuous duty?
 
  #7  
Old 01-19-11, 01:10 PM
NEC_HELP's Avatar
Member
Thread Starter
Join Date: Jan 2011
Location: USA
Posts: 21
I was just working with pre-existing 40 amp definate purpose contactors, and 30 amp DPDT power relays, and intermatic digital 120v timers,
 
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
Display Modes