where to find relay with 110v control input, for circulators

Kevin__Flynn

Jim,

You are correct. However, I would go with the SR-504. It uses a seperate isolation relay to pull in the pump relays. If you look at the diagram of both you will notice that the 504 has two additional cube relays. One is the isolation relay and one is the isolated end switch relay, I beleive. What I have experienced in the past with the 502 & 503 is that what ever is connected to the ZC terminal sees the full amp load of all the pumps.

The rest of your thinking however, is completely correct.

Kevin Flynn

Jim Cheung

EXPLANATION (no need to read): I would like the circs to run for a while after the heat call ends. Our Munchkin already has a setting to run a circ for 1-10 min after heat call ends, and according to the manual it should have the amps to run my radiator loop circ as well as the boiler loop circ. It was originally wired to the boiler loop circ only, with radiator loop circ running off a separate relay. But when I wired both circs to the Munchkin, it blew the 925 board fuse after a few weeks. Maybe this is because of the higher amp draw at startup, even though it is a slo-blo fuse.

WHAT I WANT TO DO: I want to take the boiler's 110VAC circ output and use it as control input to a relay. The relay's output will drive the circulators, thus isolating the amp load of the relay from the Munchkin.

Where do I find a relay that takes a 110VAC (NOT 24volt) control input, and has screw terminals, and if possible comes in a metal enclosure so I just have to wire the AC cables into the box?

Many thanks,

greg_28

No problem, Radio Shack stocks it, $7.99, cube relay (like the argo/taco ones) and the socket is another $3 if you want to make a control board for it. Sometime they have the 24VAC ones for switching relays alos, if your plumb supply house is out. -greggy

Jim Cheung

Yeah, I did check Radio Shack before posting, but Radio Shack sells pin-type relays (the most common kind), and their sockets are for soldering onto a board as you said.

For my purpose, it is easiest to get relays with screw terminals. Also would be nice to have a "flat" relay that fits in a standard electrical box. They make these relays that are contained in flat non-transparent enclosures, but I cn't find them.

hr

Johnstone Supply

has those flat sealed type, RBM is one brand, and they fit in a standard 2X4 electrical box.

hot rod

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Dale

relay

Why not just use an old Honeywell RA89A or R845A pump relay?Looks like a professional installation and has a nice metal box. And, you probably have some around. Just permanently jumper TT on the 24 side, out put your pump hot from 4 and power into 1 and 2. You could put a stat to tt if you chose to so the 2nd pump would only run is a certain temp was reached.

Mike T., Swampeast MO

Almost every electrical supply house will have them in stock. They're usually fully encapsulated and plug into an octal (eight pin) base. Easy to mount inside a work box or similar. DPDT 10A contact are most common I believe.

Terry

Use a Tekmar T004, 120V DPST

see www.tekmarcontrols.com

oil-2-4-6-gas

> has those flat sealed type, RBM is one brand, and

> they fit in a standard 2X4 electrical box.

> hot rod

>

> _A

> HREF="http://www.heatinghelp.com/getListed.cfm?id=

> 144&Step=30"_To Learn More About This

> Professional, Click Here to Visit Their Ad in

> "Find A Professional"_/A_

Josh M.

Ice cube relays are readily available in any electrical or controls supply house. You can get them in any voltage coil. I would goole RIB though. Stands for relay in a box. You can mount them to the side of a single gang box and use the box for all of your connections. Ice cube relays offer little mounting options. They are meant to be panel mounted on a DIN rail.

Kevin__Flynn

another possible option

if you are trying to control mutiple pumps, you could use a Taco or an Argo Pump control box with the appropriate number of pump outputs. These boxes come with a jumper between the ZC & ZR terminals. This jumper takes 110 volts from ZR to power ZC which powers the first relay or the control relay. What you would do is remove that jumper and bring your boilers 110v hot leg to the ZC terminal. When there is 110 volts present the pumps run. No 110 no run.

Make sure you bring seperate 110 to the controls input. Each seperate pump relay has a 10 amp rating.


Kevin Flynn

BigRed

R I B relays

Relay In a Box or know as a RIB relay. Coil voltage can be 24vac or 120vac and it has a male 1/2 end for mounting right to a electric box at a knock out. I know of two types one has a three posistion switch so you can toggle the contacts closed or open or auto. They work great and are very simple to use.

Jim Cheung

BRILLIANT!

I do have a Taco SR503, and after reading the instruction sheet for it, I think I understand what you are saying, and it should work very nicely...thank you!

To be very explicit, I believe I need to do the following:

1) set up the jumpers as described under "Tankless coil boiler application" in the SR503 instructions (see scan below).

2) run the thermostat wires directly to the boiler, and connect the SR503 stat input terminals with wires (i.e. short them) so the SR503 thinks the stats are always calling for heat. I believe this is an essential step, although you didn't mention it.

3) wire all the circs to the circ power outputs of the SR503.

4) take the circ power output of the boiler, and connect it to ZC. This simulates a tankless-coil boiler sending a start-circs signal. Is this correct and complete?

PS I DO NOT need zone control, all pumps can run at the same time.

J. Cricket

R. Kalia_8

Wow, I'm glad you warned me or I would have fried the Munchkin control board again. I was vaguely wondering how the SR503 could do its job with only the three circ relays, now you have told me!

I already have an SR503, which is why I liked this option. If I have to buy a $150 SR504, I'd rather put in a $20 isolation relay in a junction box. No sense in trying to fool the fancy Taco box into behaving like a simple isolation relay.

Thanks for all the help...

R. Kalia_8

GREAT RELAY, everyone should know about them!

Thank you, the RIB relays were exactly what I was looking for!

Since so many people responded in this thread by telling me to buy pin-type (ice-cube type) relays and sockets, I am giving the URL for the RIB relay below so the hydronics professionals here can see what this item is. It is VERY convenient since it is pre-packaged with an on/off/auto switch, a pilot light, surge protection, etc. It will save you time on the job.

Functional Devices RIB2401SB relay