Help a n00b install a compressor auto-drain

Thread Starter

ryanjg117

Joined Nov 3, 2017
17
So, I watched this video (linked halfway into the video where he gets to business) on YouTube and got all excited about installing an auto-drain on a 60-gallon compressor I recently scored off Craigslist, a SpeedAire 60-gallon upright compressor which, typical of most sub-$2,000 compressors, uses a pressure switch to activate the motor.

The gist of what I'd like to accomplish:
Every time the compressor motor powers on to rebuild pressure in the air tank, I'd like the timing relay to open the solenoid for a period of about one second... That's it. Oh, and I want it all powered off the 3-wire 220v coming into the compressor, no secondary 110v outlet. There are plenty of kits of Amazon for doing this, but they all require secondary 110v power connection which also means the solenoid is operating all the time... Not just when the compressor is on. I will seldom use this compressor so I'd really like an auto-drain that only fires when I'm actually using it.

Here's the components I've ordered to make this work (all capable of running on 220v):
  • Solenoid Valve, Normally Closed, 1/4" NPT, 220/50V (Asco RED HAT model 8262H202 - spec sheet)
  • Time Delay Relay, Power On Time Delay Relay, 0.2 to 5.0 seconds, DPDT (Omron H3Y-2 - spec sheet)
  • Miscellaneous 1/4" NPT brass piping (elbow and nipple) for the drain assembly
I've got the timing relay powering on as intended, I have it set for one second, and I can see the "time up" LED comes on after one second. So I think the timing relay is at least powering on and the timer is working as it should.

The solenoid has three wires, two red and one green/ground. I have one of those wires going to the always-powered side of the pressure switch, and the other red wire going to the timing relay. I've tried putting this wire in literally every other contact on this switch and it seems like the solenoid is simply not opening up for one second as I'd like.

Here's the wiring diagram for the timing relay:


Any idea what I might be doing wrong here? Thanks.
 

#12

Joined Nov 30, 2010
18,076
The solenoid has three wires, two red and one green/ground. I have one of those wires going to the always-powered side of the pressure switch, and the other red wire going to the timing relay.
Put the solenoid wire on pin 5 and add another wire to the other side of the 220 VAC power on pin 9.
If I got that backwards, put the other side of the 220V power on pin 1.
 

Thread Starter

ryanjg117

Joined Nov 3, 2017
17
Just tried both of those scenarios - solenoid L1 to pin 5, L2 to pin 9 - nothing. Then I tried solenoid L1 to pin 1, L2 to pin 9, still nothing. I'm wondering if I've got a bad solenoid valve? I double-checked and the flow direction is correct.
 

tranzz4md

Joined Apr 10, 2015
314
Your TDR pins 13&14 are wired directly across the contactor coil, (or motor leads if no contactor is used)

Jumper from 13 to 1
9 goes to one wire of your solenoid, and 14 to the other solenoid wire.
 

Thread Starter

ryanjg117

Joined Nov 3, 2017
17
Your TDR pins 13&14 are wired directly across the contactor coil, (or motor leads if no contactor is used)

Jumper from 13 to 1
9 goes to one wire of your solenoid, and 14 to the other solenoid wire.
tranzz4md, when you state "wired directly across the contactor coil (or motor leads if no contactor is used), I'm not sure what you mean as this is my first industrial control project even though sadly I worked for an industrial control company for five years... in the marketing department! Currently I've got TDR power coming from the big "L1" terminal inside the compressor pressure switch, and a power terminal on the motor itself:



When you say "jumper from 13 to 1" do you mean connect a cable between those two terminals on the TDR?
 

Thread Starter

ryanjg117

Joined Nov 3, 2017
17
tranzz4md, it works! I have no idea how or why, but it works just as I was hoping. Thanks so much - now to clean up the mess of wires and get it into a nice box. :)
 

Thread Starter

ryanjg117

Joined Nov 3, 2017
17
@tranzz4md, thanks so much for helping me here. The auto drain has been working great over the last year.

I'd like to add discrete open/close pushbuttons on the cover of my electrical box that houses the time delay relay, for when I want to drain it for, let's say, 20 seconds. Actually, maybe a toggle switch would work better here. How would such a switch be wired into my current control scheme?

Thanks!
 

Reloadron

Joined Jan 15, 2015
4,508
Just wire a N/O (Normally Open) push button or the sction of your choice across the relay contacts powering your solenoid. Effectively in parallel with the existing contacts which turn the solenoid off and on. This will bypass the timed relay making for manual operation of the solenoid. Personally I would just use a momentary push button since you can hold a button down for 20 seconds or whatever. You can also just use an On/Off toggle action requiring you to turn it on and then off.

Ron
 

Thread Starter

ryanjg117

Joined Nov 3, 2017
17
Just wire a N/O (Normally Open) push button or the sction of your choice across the relay contacts powering your solenoid. Effectively in parallel with the existing contacts which turn the solenoid off and on.
So in this case, I'll be taking a two-wire conductor from the pushbutton and connecting them to pins 9 and 14 on the time delay relay, correct? And not removing any existing wires from the time delay relay (just adding).
 

Reloadron

Joined Jan 15, 2015
4,508
I should have mentioned a switch I like in the push button type is Grayhill 4000 series. I used them in my designs for solenoid bypass all the time and I like adding the Button Guard accessory. They run about $5.00 depending on the vendor.

Ron
 

Reloadron

Joined Jan 15, 2015
4,508
So in this case, I'll be taking a two-wire conductor from the pushbutton and connecting them to pins 9 and 14 on the time delay relay, correct? And not removing any existing wires from the time delay relay (just adding).
Depends on how you are setup. Your relay out of the timing module has two sets of NO/NC contacts 9 & 1 are NC as are 12 & 4 while 9 & 5 are NO as are 12 & 8. Pins 13 & 14 are the relay coil based on the drawing back in the beginning.

Ron
 
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