2
\$\begingroup\$

I have a 1.5kW 220VAC 1 Phase dust extractor. It's controlled by what looks like a DOL switch KJD17B/5T (so I assume the 5th terminal is an overload).

KJD17B Datasheet

Wiring diagram on duct collector: From what I can see it's DP/ST and has L/N In and L/N Out and then a 5th connection form the motor which I can only assume is some sort of overload.

I'd like to add a remote start/stop, but it looks like the KJD17B is an enclosed device so I can't wire my remote start/stop in parallel/series.

I'd welcome advice on how to achieve my remote start solution? Should I try to re-wire the DC and bypass the KJD in favour of two external DOL start/stop controllers?

\$\endgroup\$
  • 1
    \$\begingroup\$ We're missing the image of the wiring diagram and the link to the datasheet. Hit the edit link under your question. \$\endgroup\$ – Transistor Nov 10 '18 at 11:26
  • 1
    \$\begingroup\$ Updated with what I have. \$\endgroup\$ – Gavin Hill Nov 10 '18 at 11:29
1
\$\begingroup\$

The fifth connection is under-voltage lock-out - notice the symbol "U<" in the little box on the switch: -

enter image description here

It also tells you on page 1 of the data sheet that there is a feature that prevents restarts should the AC fail. That connection is associated with that feature and, maybe the connection to the motor is because there is an over-temperature contact in the motor that can also trip the magnetic relay internally.

This makes adding a remote start/stop circuit somewhat problematic but, if you are fit for the task, the new start/stop circuit would need to come down stream of the KJD17B and could be the conventional self-latching relay circuit and wouldn't need to be double pole: -

enter image description here

\$\endgroup\$
  • \$\begingroup\$ Thanks Andy. So in your diagram The AC_240V would be the supply from the existing switch? I'd leave the (probable) thermal cutout from the motor in place as that would still cut-out upstream. My remote start/stop would work as long as there wasn't power loss to the existing switch as that would reset it and the AC fail feature would kick in. \$\endgroup\$ – Gavin Hill Nov 10 '18 at 11:48
  • \$\begingroup\$ Correct interpretation; the KJD has to be upstream so it still provides supervisory protection features and still latches when you press "green". \$\endgroup\$ – Andy aka Nov 10 '18 at 11:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.