Power Switch Tail 2 poor performance

[ksl177]

I'm not entirely sure what's going on, but let me describe the issue and we can go from there.

I have my BCS-460 set up to trigger some Ferwmwraps (40w @110v total) via Hysteresis using Power Switch Tail IIs (PST) as the Relays. So PWM shouldn't be in play.

Wiring is pretty simple, just the BCS out to the PST relay.

With the Fermwraps plugged directly into the power strip they heat like a champ. With the Fermwraps plugged into the PSTs they barely get warm.

Ideas?

[JonW]

In addition to the PST's, your other variable here is PWM. Do a "Direct On" in BCS instead of a PWM and see if it makes any difference. I'm betting that the fermwraps don't respond well to PWM.

[ksl177]

Pwm shouldn't be on unless i'm missing something? Also i've never changed it from the default 100%.

[JonW]

I misread your post that you were using hysteresis and that's why PWM wasn't in play.

Yeah, sounds like it should be pretty straight forward. You might plug a DMM into the strip to see if you're getting the expected voltage output or if you don't have that, just try plugging a standard light into the strip and control it just to see if you're getting full brightness out of it.

[ECC]

When you turn on the BCS output, you should hear a small click in the pst, which is the relay closing. Do you hear the click? If not, the wiring may be incorrect.

Proper wirining is to connect + to bcs output, - to bcs gnd.

[ksl177]

Nope,
wiring is correct. I do hear a click, and the indicator LED comes on. In fact on two of the outs I hear a series of rapid clicks (like the relay is cycling 100 times) before it stabilizes on.

I've used the PSTs with a Ranco before, so I know they do work.

I'm going to dig out a Multimeter tomorrow and see if I've got a good voltage out from the BCS and if I'm leaking voltage someplace. I also suspect that the lead to the PSTs might be too high impedence.

[ksl177]

So I picked up a really cheap multimeter from Harbor Freight yesterday and had a chance to check things out.

Direct from the BCS I'm getting 4.95v out both from the switched and unswitched outputs. I'm getting half the amps from the switched as the unswitched though. I'm not 100% sure if that's expected behavior or not, ECC will have to verify exactly what I should be seeing.

Now here's the fun part, and a bit of a caveat to to anyone else wiring their BCS.

In my diagrams I have an indicator LED wired in series on the backside of a HOA switch, however, being super smart and clever, I actually wired them in parallel. The thought being if an LED blows i'll still keep power. So in unswitched mode I get about 3v at half the normal amperage. In switched mode I get about 2.5v at 1/4 the amps.

So that would be the problem right there. I'm not giving the PSTs enough juice to actually actuate.

So yeah...

Going to take the LEDs out of the circuit and see if things work better, and then put them back in series and see if that fixes things.