SSR on All the Time with EKO 60

[rickh1001]

I had a problem with the EKO 60 blowing fuses in its controller, when I had it driving a Taco 0011 pump. The pump is rated at 1.75 amps I believe. As several posters have noted, this puts the total capacity of the controller near its current limit. I noticed that is only blew fuses when starting up the fans from cold, but otherwise ran fine, confirming the idea of the controller being too close to its capacity.

So I hooked up a solid state relay, using the AC signal from the EKO to turn the separate power line to the circulator on/off. However, when I tried it, the EKO turned the SSR on all the time, even when the boiler was stone cold. The green circ light on the controller would be off, but it would still power up the SSR and run the circulator.

Why is this? I hooked the EKO controller back to direct control of the circulator, and it blew the 2A fuse again, but after I replaced it, everything worked well (meaning the EKO controlled the circulator). So it seems one or both of the fans are drawing just a little too much current upon cold startup.

The main question though, is why can't I use an AC control SSR to start and stop the circulator from the EKO? Thanks for any advice.

 

[BrownianHeatingTech]

I'm assuming that the SSR is correctly-rated for this application - there are a lot of them out there, so double-check that what you have is rated for what you're doing with it.

Assuming it is...

Measure the voltage output on the controller. Even when it is not "powering" the pump, there may be some voltage leaking, which might be enough to trigger the relay. Measure it both across the terminals, and from each terminal to ground.

Joe

 

[Medman]

Joe is correct - there is a significant leakage current with the RK2001 controller on my EKO 25 - enough that I could no use a GFCI on the circuit it is powered from. I have not yet opened the box to see what if anything can be done about the leakage. Anyone out there have any ideas?
In my line of work I usually see high leakage due to poor grounds or high capacitive coupling in devices. Since I haven't looked inside yet, I don't know how the controller is made. It could be something simple.

 

[dzook]

"Why is this? I hooked the EKO controller back to direct control of the circulator, and it blew the 2A fuse again, but after I replaced it, everything worked well (meaning the EKO controlled the circulator). So it seems one or both of the fans are drawing just a little too much current upon cold startup."

The new boilers are shipping with 4 amp fuse with same controller.

This is a copy of text from the RK2001UA controller manual.

CAUTION! The maximum total power of devices connected to the
controller mustn't exceed 450W.


The 2 amp fuse previously sent with the controllers only would allow the controller to reach a maximum of approx 225 watts load at 110v before blowing. The 2 amp fuse is half of what the controller allows.

Replace with 4 amp fuse and it should work without relays.

 

[Sizzler]

Mine blew fuses about every fire so I replaced the 2 amp with 4 amp from Radio Shack. Have not had a blown fuse since.