Taco switching relay exp

Steve_75

I have two Taco expandable switching relays - SR 504 (4 zone) and SR 506 (6 zone). Each relay seems to work fine on its own but when I connect them via the 4 wire connection block they become erratic.
All of the zone lights come on in the slave control. If I pull the fuse then the lights correct themselves with only the green and any zone calling. The control works fine until the zone is satisfied. When a new zone then has a call for heat the control will buzz until I re-insert the fuse - which causes all the lights to light. As before the buzzing stops and the lights go out when I pull the fuse.
Also, the end switch pulls in some time but not all of the time. I am using this to pull in a 845 to start my main circulator for the heat transfer and need this on when any of the 6 zones of radiant call for heat. Now it comes on when any of the 10 zones (4 are baseboard) call.
This is a pretty simple hook up with 4 wires connecting the two - could I have a bad control or do I have something set wrong? Wire pinched?

R Stone

Taco Relay

> I have two Taco expandable switching relays - SR

> 504 (4 zone) and SR 506 (6 zone). Each relay

> seems to work fine on its own but when I connect

> them via the 4 wire connection block they become

> erratic. All of the zone lights come on in the

> slave control. If I pull the fuse then the lights

> correct themselves with only the green and any

> zone calling. The control works fine until the

> zone is satisfied. When a new zone then has a

> call for heat the control will buzz until I

> re-insert the fuse - which causes all the lights

> to light. As before the buzzing stops and the

> lights go out when I pull the fuse. Also, the

> end switch pulls in some time but not all of the

> time. I am using this to pull in a 845 to start

> my main circulator for the heat transfer and need

> this on when any of the 6 zones of radiant call

> for heat. Now it comes on when any of the 10

> zones (4 are baseboard) call. This is a pretty

> simple hook up with 4 wires connecting the two -

> could I have a bad control or do I have something

> set wrong? Wire pinched?

R Stone

Taco Relay

Do you have the master relay on master and the slave set to slave. Also is polarity correct in connecting the two.

Steve_75

Yes the master and slave switchs are correct. Not sure what you mean regarding polarity. The controls are ganged by 4 low voltage wires. Pretty hard to screw up as they go into a numbered block 1-4 and the wires are color coded. I did use CAT 5 wire which is 24 gage and the control calls for 18-22 gage. CAT 5 is 4 pairs of wire so there are 2- 24 gage wires per terminal and it is clear they are connecting as it causes the problem. I have checked the ends very closely to be sure they are not touching and are engaged.

R Stone

What I meant was are the wires going from one relay to the other the same. For example red to one green to two and so on. It sounds like you have them right. I know it is straight foward. Stupid question but why cant you run them independent of one another. Is there a 702/705 control?

Ronco_2

taco relays

Are there factory jumpers installed on the relay? My next question would be did you hook up l1 correctly? I once hooked up power to the p terminal on an argo control instead of the correct l1 terminal and it gave me similar troubles. I was foolish enough to change out the control and geuss what, pu-pu on me it did the same thing. I rechecked the wiring diagram and sure enough I had it wrong. My apprentice was quick to point out even a master can make simple mistakes.

Jed_2

Seems to me

you could use the ZR output to power your primary

Steve_75

Couple things - I can't run them independent as I need the burner to come on when a zone calls and I wanted to keep priority for the hot water zone (cold start boiler)
I also thought I could run the primary off from ZR and it seems to work some of the time.
The control does have jumpers but just on the ZR ZC side - as I said it is a cold start boiler. I did try taking them off just in case but nothing changed.
Could a wire be pinched? The controls are in seperate rooms with a 25' run of wire and I am wondering if a staple could be causing this. I am going to run a seperate wire across the florr to see if that fixs the issue.
Thanks for all of the input.

AJ3

Do you have the SR panels powered off the same 120VAC circuit? If not, make sure they are being powered off the same circuit.

Joe Mattiello

Taco, expandable Master/Salve exp relay boards

Boards should have master/slave orientation powered with the same circuit, or use a pig tail from the master board to the slave board. Additionally, the boiler should be on the same circuit. The expansion terminals 1,2,3,4 on the master board should be wired to the corresponding terminals on the slave board. If wires are crossed, that would help explain the erratic behavior, and why the boards work independently but will not interface with each other. Try removing all four wires, and methodically replacing them until you have uncovered the root cause of the problem.

Taco, Inc.
Joe Mattiello
Technical Service Technician
joemat@taco-hvac.com
401-942-8000 X 484
www.taco-hvac.com