Hi all, first-time poster, professional builder but very amateur electrician.
I am trying to wire 2 circulator pumps in a plumbing project, according to the following needs:

1/ Recirculation pump
To be run for about 30 sec whenever anyone pushes a button near a (remote) sink. This will refresh the hot water in the pipes.
Bought a cheap Chinese DPDT 110v timer (Omron H3Y-2) from Amazon. Have it powered up via the 'Control' terminals, but no power showing up at any of the other screws, no matter what phase it's in.
Wondering if it's defective, or if it's supposed to get 120v at the 'Load' screws, and the 'Control' connectors are for the switch?
I bought this with the understanding that a simple close-circuit switch would trigger the load circuit to close, and the timer to initiate.
Right now the timer function seems to work when power is applied to 13/14, but again no juice showing up anywhere else, either at the PW phase or the UP. Photo below. Thoughts?

2/ Circ pump:
To circulate a buffer tank through the boiler, whenever *any* of the following conditions is present:
- buffer tank falls below a certain temp;
- room next door t-stat calls for heat;
- domestic hot water is running;
- hydronic heat circ pump is running.
My thought was to use 4 separate Solid State Relays, wired in parallel, so that any of those 'triggers' would energize the circ pump, but NOT energize each other (!)
Only problem is, if all 4 of the 'hot' leads off the SSRs are connected to the same terminal on the pump, how does that 120v not 'backwash' into the other 3 SSRs? And, if it does, would that damage anything? (See, total newbie here.)

Would appreciate any guidance. Thanks!

 

#1 Look up "dry contact" the contacts of the relay are not powered you must wire them as you would any switch. (in series with the load)

You want to use contacts 5 and 9 or 8 and 12 these are the NO (normally open) contacts.

EDIT: that timer seems to be "on delay" I don't think that is what you want.

#2 should work as you planed.

But you should show a diagram of how you intend to wire it up and what kind of relays you intend to use.

 

#1 Look up "dry contact" the contacts of the relay are not powered you must wire them as you would any switch. (in series with the load)

You want to use contacts 5 and 9 or 8 and 12 these are the NO (normally open) contacts.

EDIT: that timer seems to be "on delay" I don't think that is what you want.

Hmmm. Here's a schematic of it working in OFF-DELAY mode (below), according to Amazon.
But I see now that it needs 'hot' at the 13 terminal to 'trigger' the timer cycle. That won't work for my application. I needed a simple instantaneous remote push-button to cycle the circ pump for half a minute.
Looks like I'll be ordering a Macromatic 11-pin like so:
https://www.grainger.com/product/MACROMATIC-Single-Function-Time-Delay-23NV03?opr=ILOF
(Any reason THIS one won't work?)
Thanks!

 

Then there's this interesting graphic, also from Amazon.
It would seem to indicate that 110v hot and neutral come into the relay at 9 and 12, go out to the motor at 5 and 8, and are 'controlled' by some (smaller?) input voltage (or maybe an instantaneous switch?) at 14 and 13.
Am I reading this right?

 

Yes, that Grainger relay will do what you want, but you still have to understand how to wire dry contacts.

Be sure to get a socket.

 

Yes, that Grainger relay will do what you want, but you still have to understand how to wire dry contacts.
Be sure to get a socket.

Yeah, I took a while picking out a socket, but they all seem to be Chinese, even though they have names like Dayton and Eaton.

 

you still have to understand how to wire dry contacts

The original Omron relay clearly shows AC power to terminals 13/14, correct? So it's a 'wet' relay, not a 'switch' relay? Meaning it should show power *through* the relay to one of the 'send' terminals, depending on relay state, correct? Multiple YT videos of this same relay show power through the unit without any 'dry' wiring...

 

I'm not going to argue with you.

Do you see any connections from the AC inputs to any of the other contacts?

 

I'm not going to argue with you.

Do you see any connections from the AC inputs to any of the other contacts?

View attachment 301649

I do not. Thanks, I wondered about that. Dry contacts, here we come!

 

View attachment 301649

OK, forgive me sounding this out here:

1/ A dry contact relay is like a light switch. It interrupts power when switch is off, and flows when switch is on.

2/ So it should have 2 separate circuits: A) a 'switch' circuit that energizes the relay, like flipping the light switch; and B) a 'flow' circuit that connects separate input power to output;

3/ The 'switch' circuit is connected at the 'control' terminals;
The 'flow' circuit is connected at the 'common' terminals.
Correct so far?

4/ In a Normally Open circuit, the circuit is closed when the relay is energized, and power flows from the Common terminal(s) to the NO terminal(s).
In a Normally Closed circuit, the circuit is opened when the relay is energized, and power is *interrupted* from the Common terminal(s) to the NC terminal(s) (i.e. power is always at the NC terminal(s) *except* when the relay is energized).

5/ In the Omron H3Y-2, it looks like
- the 'switch' contacts are 13/14, they are AC, and that's all they do - flip the relay ON or OFF;
- the Common terminal(s) are 9/12, and those accept the current being controlled (looks like that could be anything, AC or DC current, of a large range of voltages);
- the NO terminals are 5/8 - current from the Commons should appear here when the relay is *activated*;
- the NC terminals are 1/4 - current from the Commons should appear here when the relay is *not* activated.
How'm I doing?

6/ The TIMER function of the H3Y-2 *should* maintain current to the NO terminals, and interrupt it to the NC terminals, for the duration of the time set.

Questions:
- So I need a light switch to control the light switch? I.e. I need 110v AC to appear at the 'Control' terminals of the Omron to energize the relay?
- I would hook up a *separate* 110v AC circuit to feed the recirc pump, from the Commons to the NO terminals?
- Does the Omron need to be energized the whole time I want the NO timer to be active? I.e. like an actual light switch that's flipped on? Omron energizes, connects Commons to NOs, holds them connected for the duration of the timer, then diconnects Commons and NOs, even though relay is still energized?
- So upstairs in the remote bathroom, the next time someone came it, they would flip the wall switch off, and then on again to restart the cycle? The Omron could not be fed by an instantaneous push-putton switch, even if it supplied 110v AC?

I assume simply short-circuiting across 13/14, like a simple instantaneous switch, would not 'energize' the relay in any way, or initiate the timer cycle from Commons to NOs? It requires actual 110v AC at the Control terminals to operate?

How is the Micromatic relay different, then, since it *does* allow a simple trigger circuit-completion switch to initiate the timer cycle?

Thanks for your patience, AAC!

 

On the Macromatic, looks like it's actually pretty similar to the Omron. Only difference is the extra 3 pins, 2 of which give me the 'short' trigger option. Otherwise, is this right?
- 1/11 are the Commons?
- 2/10 are the control (110v AC)?
- 3/4 and 8/9 are the NO/NC, depending which way you hook them up?
- 5/6 is the 'short' trigger?
- WTF is 7 for??

 

Also, on the 8-pin Omron, is there any reason why you couldn't rig a remote 'light' switch to interrupt the power to the Control terminals?
And is there any reason why it couldn't interrupt the Neutral instead of the Hot? Wouldn't that be safer? Wouldn't interrupting either de-energize the relay?
And finally, does the relay need to be energized continually through the whole Timer cycle, or only momentarily?
Thx again!

 

1/ A dry contact relay is like a light switch. It interrupts power when switch is off, and flows when switch is on.
Correct for a basic relay, but not one with a timer function, then the timer function must be taken into account.

2/ So it should have 2 separate circuits: A) a 'switch' circuit that energizes the relay, like flipping the light switch; and B) a 'flow' circuit that connects separate input power to output;
Correct

3/ The 'switch' circuit is connected at the 'control' terminals;
The 'flow' circuit is connected at the 'common' terminals.
The "common" terminal switches between the normally open position and the normally closed position.

4/ In a Normally Open circuit, the circuit is closed when the relay is energized, and power flows from the Common terminal(s) to the NO terminal(s).
In a Normally Closed circuit, the circuit is opened when the relay is energized, and power is *interrupted* from the Common terminal(s) to the NC terminal(s) (i.e. power is always at the NC terminal(s) *except* when the relay is energized).
Correct, except when a timer is involved.

5/ In the Omron H3Y-2, it looks like
- the 'switch' contacts are 13/14, they are AC, and that's all they do - flip the relay ON or OFF;
Yes, but it also starts the timer function. It would be better to use "control" and leave "switch" for the contacts.
- the Common terminal(s) are 9/12, and those accept the current being controlled (looks like that could be anything, AC or DC current, of a large range of voltages);
Correct, but the important thing is to switch the "hot" and not which terminal you choose to "accept the current."
- the NO terminals are 5/8 - current from the Commons should appear here when the relay is *activated*;
Correct
- the NC terminals are 1/4 - current from the Commons should appear here when the relay is *not* activated.
Correct

6/ The TIMER function of the H3Y-2 *should* maintain current to the NO terminals, and interrupt it to the NC terminals, for the duration of the time set.
No, the duration of a "delay on" delays the action of the terminals when the power is applied to contacts 13 and 14.

Questions:
- So I need a light switch to control the light switch? I.e. I need 110v AC to appear at the 'Control' terminals of the Omron to energize the relay?
Correct
- I would hook up a *separate* 110v AC circuit to feed the recirc pump, from the Commons to the NO terminals?
I think you will need to use the NC connections because this is a delay on timer.
- Does the Omron need to be energized the whole time I want the NO timer to be active? I.e. like an actual light switch that's flipped on? Omron energizes, connects Commons to NOs, holds them connected for the duration of the timer, then diconnects Commons and NOs, even though relay is still energized?
The relay will need to be energized the entire time and de-energized to restart a timer period.
- So upstairs in the remote bathroom, the next time someone came it, they would flip the wall switch off, and then on again to restart the cycle? The Omron could not be fed by an instantaneous push-putton switch, even if it supplied 110v AC?
You could use a NC push button.

I assume simply short-circuiting across 13/14, like a simple instantaneous switch, would not 'energize' the relay in any way, or initiate the timer cycle from Commons to NOs? It requires actual 110v AC at the Control terminals to operate?
DO NOT short the 13 & 14 terminals! You must open the circuit.

How is the Micromatic relay different, then, since it *does* allow a simple trigger circuit-completion switch to initiate the timer cycle?
This relay is "delay off" with a trigger. You simply leave the power connected to the control contacts and use the trigger to restart the cycle.
It is much more straight forward.

The operation of the H3Y-2 should be as follows...
Connect the power to the control contacts with a NC push button. 13/14
Connect the power to the load thru the NC contacts of the relay, either set.
Then when you push the button, power is disconnected to the relay and the cycle starts, where the common moves to the NC connection and then to the NO at the end of the cycle. See edit in post #20 below.
You may need a delay during the button push.

I hope this is correct.

 

- 1/11 are the Commons? Correct
- 2/10 are the control (110v AC)? Correct
- 3/4 and 8/9 are the NO/NC, depending which way you hook them up? Correct
4 and 8 are NC.
- 5/6 is the 'short' trigger? Correct
- WTF is 7 for?? No Connection
View attachment 301671

 

Also, on the 8-pin Omron, is there any reason why you couldn't rig a remote 'light' switch to interrupt the power to the Control terminals?
I don't really know enough about these products to answer that, it may well restart the time cycle.
And is there any reason why it couldn't interrupt the Neutral instead of the Hot? Wouldn't that be safer? Wouldn't interrupting either de-energize the relay?
It would work either way, but it is standard procedure to switch the hot.
And finally, does the relay need to be energized continually through the whole Timer cycle, or only momentarily?
Continually

 

1/ A dry contact relay is like a light switch. It interrupts power when switch is off, and flows when switch is on.

The definition of a Dry-Contact is one that does not interrupt or switch the source of power.
IOW, contact is only make or broken when no source of power exists.
As in an enable only contact.

 

The operation of the H3Y-2 should be as follows...
Connect the power to the control contacts with a NC push button. 13/14
Connect the power to the load thru the NC contacts of the relay, either set.
Then when you push the button, power is disconnected to the relay and the cycle starts, where the common moves to the NC connection and then to the NO at the end of the cycle.
You may need a delay during the button push.

I hope this is correct.

That is not correct.

The Omron and the Macromatic relays both suffer the same limitation, and it is a limitation that is shared by 99% of timer relays on the market: they have electronic timing circuits inside that don't do anything without power. You take the power off pins 13/14 and no "cycle starts," rather, the relay goes back to its rest state.

Any OFF-delay timer relay you are likely to encounter, will need constant power. In the case of an OFF-delay timer (which is what the macromatic is) there will be a separate input for the signal which is supposed to, upon transition to 0v, begin the timed cycle. But even once this signal goes to 0V the relay itself (the "coil") still must have power - for the electronic timing circuit inside.

Once upon a time there were off-delay timers which worked just the way you described but they worked on totally different principles. They could achieve timing even without the presence of power. They used pneumatic components to achieve this. When power was applied, the relay would change states and air would be drawn into a reservoir. A plunger in the reservoir would keep the relay switched even after power was removed from the coil. After power was removed, air would bleed out of the reservoir at a rate controlled by an orifice valve until there wasn't enough pressure to resist the relay spring and then it the relay would switch back to its rest state. These still exist but are very niche items, expensive, and hard to find.

@rbpaac you need to ditch that omron relay. It's actually a good quality brand, Japanese, not Chinese (assuming it isn't a knock-off) but it's purely an on-delay relay and is not suitable for what you are trying to do. But I'm sure there are off-delay relays available for less whatever outrageous price grainger wants.

 

Also, on the 8-pin Omron, is there any reason why you couldn't rig a remote 'light' switch to interrupt the power to the Control terminals?
I don't really know enough about these products to answer that, it may well restart the time cycle.
And is there any reason why it couldn't interrupt the Neutral instead of the Hot? Wouldn't that be safer? Wouldn't interrupting either de-energize the relay?
It would work either way, but it is standard procedure to switch the hot.
And finally, does the relay need to be energized continually through the whole Timer cycle, or only momentarily?
Continually

THANK YOU for all those very thorough answers!
I think I have half a clue now (or maybe a 1/4).
Onward!

 

That is not correct.

The Omron and the Macromatic relays both suffer the same limitation, and it is a limitation that is shared by 99% of timer relays on the market: they have electronic timing circuits inside that don't do anything without power. You take the power off pins 13/14 and no "cycle starts," rather, the relay goes back to its rest state.

Any OFF-delay timer relay you are likely to encounter, will need constant power. In the case of an OFF-delay timer (which is what the macromatic is) there will be a separate input for the signal which is supposed to, upon transition to 0v, begin the timed cycle. But even once this signal goes to 0V the relay itself (the "coil") still must have power - for the electronic timing circuit inside.

Once upon a time there were off-delay timers which worked just the way you described but they worked on totally different principles. They could achieve timing even without the presence of power. They used pneumatic components to achieve this. When power was applied, the relay would change states and air would be drawn into a reservoir. A plunger in the reservoir would keep the relay switched even after power was removed from the coil. After power was removed, air would bleed out of the reservoir at a rate controlled by an orifice valve until there wasn't enough pressure to resist the relay spring and then it the relay would switch back to its rest state. These still exist but are very niche items, expensive, and hard to find.

@rbpaac you need to ditch that omron relay. It's actually a good quality brand, Japanese, not Chinese (assuming it isn't a knock-off) but it's purely an on-delay relay and is not suitable for what you are trying to do. But I'm sure there are off-delay relays available for less whatever outrageous price grainger wants.

Very interesting, thanks! (The Omron *is* a cheap China knockoff, judging from the misspelling of 'botton.' Unless that's a real word in electronics??)

 

@strantor You are correct, I should have said...

Then when you push the button, power is disconnected to the relay and when the button is released the power is restored and the cycle starts, where the common moves to the NC connection and then to the NO at the end of the cycle.

i made the mistake of assuming the OP would understand that the button must also be released.

The text is now highlighted in my above post.