ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
Recent Posts
VFD MotorFeeders
by gfretwell. 10/19/17 01:02 AM
Generator Cable Sizing
by brsele. 10/18/17 07:39 PM
What do you do?
by gfretwell. 10/17/17 01:08 AM
Good ol' copper pipe in the fuse holder trick
by HotLine1. 10/16/17 07:16 PM
Another generator question
by HotLine1. 10/16/17 07:02 PM
New in the Gallery:
Gallery Test
Popular Topics(Views)
241,392 Are you busy
177,352 Re: Forum
168,962 Need opinion
Who's Online Now
1 registered members (ampherder), 58 guests, and 12 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
Page 1 of 2 1 2
#169678 - 10/11/07 05:29 PM relay with timer  
waterdog  Offline
Joined: Jun 2004
Posts: 11
I have just recently acquired my electrical contracting license here in AZ. My backround is new commercial construction. Every company I have worked for, had at
least one control guy who did the control work. I understand the basics, but my knowledge of available components for a particluar application is weak. Now that I am on my own, diving in seems to be the quickest way to accelerate the learning curve. I am hoping you guys will tolerate my ignorance

I looking for a relay with timer. It must be 120v control 120v 20 amp load. with timer sequence beginning after control power has been switched off, direct mount socket. It's gonna control a 1/4 horse E fan in a restaurant.


Work Gear for Electricians and the Trades

#169679 - 10/11/07 06:50 PM Re: relay with timer [Re: waterdog]  
michaelpwalton1  Offline
New Member
Joined: Aug 2007
Posts: 6
Do you have a "Grainger" catolog? They offer tons of diferent control relays along with very good discriptions about their usage. Or go to Armed with their information, you can then decide which Manufacturer to use.

#169680 - 10/11/07 07:14 PM Re: relay with timer [Re: michaelpwalton1]  
resqcapt19  Offline
Joined: Nov 2000
Posts: 2,148
I like this time delay relay as you can do almost any timing function that you can think of if you by the 11 pin version. The contacts are rated at 10A restive and 1/3hp 120/240 VAC.


#169682 - 10/11/07 08:30 PM Re: relay with timer [Re: resqcapt19]  
InspectorE  Offline
Joined: Oct 2004
Posts: 51
Hudson WI USA
Another common brand is Omron relays. They have numerous types of sequences, ratings, times, etc.

I suspect most of the bigger supply shops carry them.

#169683 - 10/11/07 09:01 PM Re: relay with timer [Re: InspectorE]  
electure  Offline

Joined: Dec 2000
Posts: 4,262
Fullerton, CA USA
Grainger's multifunction Dayton relay has worked pretty well for me:

#169687 - 10/11/07 11:37 PM Re: relay with timer [Re: electure]  
gfretwell  Offline

Joined: Jul 2004
Posts: 9,123
Don that TRDU120A3 is a nice product but they want $65 for it.

Greg Fretwell

#169689 - 10/12/07 01:47 AM Re: relay with timer [Re: gfretwell]  
waterdog  Offline
Joined: Jun 2004
Posts: 11
Thank you all for the quick reply

#169883 - 10/18/07 10:52 PM Re: relay with timer [Re: waterdog]  
AndyM  Offline
New Member
Joined: Oct 2007
Posts: 6
Quincy MA USA

Just a quick note that you may have already realized. To accomplish what you want with most of the relays suggested you must have a constant 120V to the relay & you control the relay thru the switch terminals. So if you remove the 120V control power to the relay the output contacts will open up immediately. The only manufacturer that I know of that makes a relay that would be a time delay off relay w/o constant control power is an Agastat timer. They are expensive but very reliable.

I have learned this info the hard way. Good luck.

#169901 - 10/19/07 10:20 AM Re: relay with timer [Re: AndyM]  
sabrown  Offline
Joined: Dec 2002
Posts: 302
Ogden, Utah, USA
Thanks AndyM, and you are correct, though pnuematic timers are available from many manufacturers Square D, Allen-Bradley, etc..

For those unfamiliar with them, they went out of style and are not commonly used anymore for general use mainly due to the far greater cost (list $300 and up versus under $100). They are also limited because of their mechanical nature to relatively short timing cycles and somewhat sloppy repeatablitiy typically around 10-15%.

AndyM, I am impressed with Agastat's wide range of timings available. I will have to keep that in reference somewhere in the back of my mind. They will work well for generator off delay timing where they will simplify the control circuitry for minimum run times and generator cooldown.


#169902 - 10/19/07 11:10 AM Re: relay with timer [Re: sabrown]  
AndyM  Offline
New Member
Joined: Oct 2007
Posts: 6
Quincy MA USA
I work in the electric power industry & we use Agastats all the time. Most of these applications are on 125VDC control circuits. They are built well & last.

I have recently had a SCADA/control job where I learned the hard way the difference between these 2 types of time delay off relays.

Interesting to hear other fields don't use the pnuematic type much. Nice to learn what is happening outside my field.


Page 1 of 2 1 2

Member Spotlight
Posts: 22
Joined: August 2009
Show All Member Profiles 

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman


Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.016s Queries: 16 (0.003s) Memory: 0.8187 MB (Peak: 0.9993 MB) Zlib enabled. Server Time: 2017-10-19 12:34:47 UTC