Transformer, Relay, Low Voltage

Kermit911 · 12-21-2010, 01:29 PM

Hello everyone, I found this site through Google and thought you guys might be able to help me out.

For Christmas I am installing a VacPan in my fathers kitchen. A VacPan is an attachment that goes to a central vacuum system. I am trying to connect it up to a shop vac out in his garage. The VacPan has a low voltage foot switch that turns on the vacuum. Here is where the small problem comes in to play. (Stupid Low Voltage) but safety first right?

From my understanding I will need a 120VAC Transformer to 12VDC then a 12VDC Relay to control the 120VAC. I attached a diagram, I hope it uploaded. If this is correct my next problem is where do I find this stuff? Radio Shack now a days sucks, Home Depot has no clue, as does Loews. I just need to make sure I am buying the correct stuff and wiring it right.

Thanks everyone
Dave

jbfan · 12-21-2010, 02:41 PM

A door bell transformer and an ice cube relay.
You may have to go to a supply house to get the relay.

Kermit911 · 12-21-2010, 03:12 PM

Great idea for the transformer, thanks! Now it comes down to the relay.

Dave

WDR · 12-21-2010, 06:11 PM

There are a lot of companies online that have electrical components, I have had good luck with McMaster Carr.

joed · 12-21-2010, 06:20 PM

A door bell transformer is only a transformer. You indicate DC voltage on your drawing. You need more than just a transformer to get DC.

Or you need an AC relay not a DC one.

Kermit911 · 12-21-2010, 07:46 PM

See... there in lies the problem. I know what I need (vaguely), I know I need a transformer to lower the voltage, and I know I need a relay that the lower voltage can switch to turn on the higher voltage. Now it is the specifics that I need help with. There are soooo many transformers and relays I'm not sure "exactly" what I need. Any ideas?

Do I need DC? No, but I belive DC is safer then AC correct?
Does the low voltage have to be 12V? No, it can also be 24V but the transformer and the relay have to match. So I don;t want to buy a transformer not knowing if the relay is going to work with it or not. Got to LOVE electricity, one little thing will change everything... then blow up.

Lets try this, will this work for what I am trying to do?
http://cgi.ebay.com/ws/eBayISAPI.dll...=STRK:MEWAX:IT
I know it is 24V that's fine and I know it is probably AC current not DC which I am also fine with. As long as it works.

Thanks
Dave

joed · 12-21-2010, 08:10 PM

Here is one ready made for you.

http://www.pennstateind.com/store/LRMSET110.html

Keep everything AC and you will be fine. The contacts on the relay need to be motor rated. A vacuum is a significant load. A tiny isn't going to cut it.

Here is one example of a motor contactor.

WDR · 12-21-2010, 08:21 PM

This relay and transformer should together. You would have to cut the plug off of the adapter cord and get a box to put the relay in.The relay has quik connect terminals, you can get the matching ones at a auto parts store or order them, you could also order a box for the relay

this is the transformer item # 70235K68

this the relay item # 7678K41

they are both from www.mcmaster.com

Kermit911 · 12-21-2010, 09:07 PM

You guys ROCK!!! I think I might like it here. Thanks for all the help everyone and all the suggestions.

12-21-2010, 01:29 PM	#1
Kermit911 Newbie Join Date: Dec 2010 Location: Delaware Posts: 5	Transformer, Relay, Low Voltage Hello everyone, I found this site through Google and thought you guys might be able to help me out. For Christmas I am installing a VacPan in my fathers kitchen. A VacPan is an attachment that goes to a central vacuum system. I am trying to connect it up to a shop vac out in his garage. The VacPan has a low voltage foot switch that turns on the vacuum. Here is where the small problem comes in to play. (Stupid Low Voltage) but safety first right? From my understanding I will need a 120VAC Transformer to 12VDC then a 12VDC Relay to control the 120VAC. I attached a diagram, I hope it uploaded. If this is correct my next problem is where do I find this stuff? Radio Shack now a days sucks, Home Depot has no clue, as does Loews. I just need to make sure I am buying the correct stuff and wiring it right. Thanks everyone Dave Attached Thumbnails Last edited by Kermit911; 12-21-2010 at 01:52 PM.

12-21-2010, 02:41 PM	#2
jbfan Electrical Contractor Join Date: Jun 2004 Location: Newnan GA Posts: 5,081	Transformer, Relay, Low Voltage A door bell transformer and an ice cube relay. You may have to go to a supply house to get the relay. __________________ Yes I am a Pirate, 200 years too late. "Jimmy Buffett"

12-21-2010, 03:12 PM	#3
Kermit911 Newbie Join Date: Dec 2010 Location: Delaware Posts: 5	Transformer, Relay, Low Voltage Great idea for the transformer, thanks! Now it comes down to the relay. Dave

12-21-2010, 06:11 PM	#4
WDR Member Join Date: Aug 2010 Posts: 94	Transformer, Relay, Low Voltage There are a lot of companies online that have electrical components, I have had good luck with McMaster Carr. Last edited by WDR; 12-21-2010 at 07:26 PM.

12-21-2010, 06:20 PM	#5
joed Member Join Date: Mar 2005 Location: Welland, Ontario Posts: 6,104	Transformer, Relay, Low Voltage A door bell transformer is only a transformer. You indicate DC voltage on your drawing. You need more than just a transformer to get DC. Or you need an AC relay not a DC one. __________________ Do not PM with questions that can be asked in a forum. I will not respond.

Transformer, Relay, Low Voltage