SqD Power Logics; momentary vs continuous relay

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brantmacga

brantmacga

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Had a project recently where the customer wanted to add programmable lighting controls on their building.

They had an NQ panelboard, so rather than installing lighting contactors, I used SqD Powerlink remote switching breakers as the cost in material was half what the contactors would've been, and the labor was exponentially lower.

The issue is that the breakers do not reliably switch off/on. Usually on each cycle, at least one breaker will not switch. The label on the power supply (as shown in pic below) says "non-continuous duty cycle, 2 seconds min recharge time....". I called square d before ordering all of this and they told me that continuous contact relays would be fine. I'm wondering though if that is part of my issue? I have programmable timers connected to 24vdc ice cube relays. SqD also recommended 3 breakers per power supply, and I have divided them as such.

Anyone have experience with these? Have you seen this problem?

We did multiple setups like this, and so far only the one that is giving me problems.

605f0c4b8dbde1d48ca36a63c978ddaa.jpg



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The non-continuous rating on the power supply, means it should not be used to power something that is 'always on' like a timer or a 24vdc relay.
That Powerlink power supply is probably intended to supply power for the length of time it takes a breaker to cycle open or closed. After 2 seconds of rest, it can power another operation.
 
As I recall, inside is a tiny little DC solenoid that is powered from a capacitor. When you close the control switch, you are discharging the capacitor through the solenoid coil, it pulses, moving the breaker handle. After its done, a flip-flop circuit reverses the polarity for the next operation and when the control circuit is open, the capacitor recharges. But if you never open the control switch, the capacitor is continuously discharging through the solenoid coil, so it never builds up a charge again and never flip-flops. So someone at Sq.D telling you it's OK didn't understand how they work. They may have been thinking only of whether or not the solenoid or capacitor would be damaged, and probably not, it's very low energy involved. But functionally, the control switch being momentary is part of the cycle of how it works.
 
We use the Powerlink systems at all of our new facilities and have been pretty pleased with it.

Assuming you have access to the G3 controller and the LCS advanced software, you can check the output status of the relay breakers in the panel. If one relay breaker continually doesn't operate, I'd assume it's not tied to the input control. If the LCS software shows it should be on and it is still off, possibly bad rail? or bad breaker? But I'd check to make sure the inputs are designated to all of the corresponding breakers.

In the set up of the system you can toggle inputs between momentary or maintained or variations of those depending on what you need.

And I'm not sure why they would say 3 relay breakers per power supply? I believe the maximum # of controllable relay breakers is somewhere around 80..... Because we have slaved multiple panels off of one G3 controller as long as it meets the maximum footage allowed.
 
WiscElectrician said:
And I'm not sure why they would say 3 relay breakers per power supply?
Click to expand...

The PowerLink system has many different components. The OP had a picture of a specific power supply with the limited ratings. The system you describe uses a different power supply.
 
brantmacga said:
...
The issue is that the breakers do not reliably switch off/on. Usually on each cycle, at least one breaker will not switch. The label on the power supply (as shown in pic below) says "non-continuous duty cycle, 2 seconds min recharge time....". I called square d before ordering all of this and they told me that continuous contact relays would be fine. I'm wondering though if that is part of my issue? I have programmable timers connected to 24vdc ice cube relays. SqD also recommended 3 breakers per power supply, and I have divided them as such.
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Click to expand...
Does this happen to be on a 208Y/120 system? If so, catalog recommends only 2 breakers per power supply.
 
Smart $ said:
Does this happen to be on a 208Y/120 system? If so, catalog recommends only 2 breakers per power supply.
Click to expand...

Aaaaaaahhhhhhggggggg yes !!!!

Where did you see that ?!?! I looked for it before calling square d.


No, we don't have a G3 controller . I'm using QOBPLPS with QOB120PL breakers; these have pigtail connections, not the daisy chain connectors.

I have them connected to Grasslin timers via an ice cube relay.


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