Thread: Switch on generic 2 HP duct collector

Just seen this thread which answers my query

https://www.bunnings.com.au/arlec-re...utlet_p4331763
Wireless Remote is simpliest and cheapest.

Yes that's true but it doesn't work if the effect of turning off the power at the switch isolates the circuit at the DC end. Hence you have to either:
1. replace the DC switch with one that does not isolate when the power is turned off at the powerpoint (including through a wireless remote),
2. ensure the on switch at the DC is mechanically kept in the On position all the time, or
3. bypass the DC switch.

Originally Posted by jmk89

Yes that's true but it doesn't work if the effect of turning off the power at the switch isolates the circuit at the DC end. Hence you have to either:
1. replace the DC switch with one that does not isolate when the power is turned off at the powerpoint (including through a wireless remote),
2. ensure the on switch at the DC is mechanically kept in the On position all the time, or
3. bypass the DC switch.

4. Put a small 1OA power outlet After the DC switch and wire the motor to a 10A plug so that you can use a wireless remote and still have the DC switch turn OFF and remain OFF if there is a UTILITY power outage. YOU will need to push the DC switch on ONCE.

I've blown two 10A wireless switch units, my DC seems to draw more like 15 on start up.. or at least my 'leccy seems to think so...

AC motors have about 7 times start up current - so a 10A motor can draw up to 70 amps when starting so normal 10A contacts in a wireless unit will burn out as you have found. If you have a tamed sparky that drinks (spolier: most of us do) get him to wire your wireless remote output onto a control contactor. The contactor does the heavy lifting and your wireless unit will last for ages.

Originally Posted by reuelt

4. Put a small 1OA power outlet After the DC switch and wire the motor to a 10A plug so that you can use a wireless remote and still have the DC switch turn OFF and remain OFF if there is a UTILITY power outage. YOU will need to push the DC switch on ONCE.

It would be simpler to hardwire one of these in between the DC switch and the DC.
https://www.ebay.com.au/itm/271968342893

Originally Posted by david.elliott

I've blown two 10A wireless switch units, my DC seems to draw more like 15 on start up.. or at least my 'leccy seems to think so...

2HP DCs draw up to ~30A on start up.
The ones above handle more 15A continuously and 30A peak power.

Originally Posted by maxxsinner

AC motors have about 7 times start up current - so a 10A motor can draw up to 70 amps when starting so normal 10A contacts in a wireless unit will burn out as you have found. If you have a tamed sparky that drinks (spolier: most of us do) get him to wire your wireless remote output onto a control contactor. The contactor does the heavy lifting and your wireless unit will last for ages.

Unfortunately 2HP DCs (or almost any small DC for that matter) don't use a contactor.

Was just suggesting getting one installed Bob.
I have done a few for the gents at the local mens shed using this type of enclosure with a single pole contactor and bypassing the on motor push button relay.

https://www.clipsal.com/Trade/Produc...1&sg=120641052

Originally Posted by maxxsinner

Was just suggesting getting one installed Bob.
I have done a few for the gents at the local mens shed using this type of enclosure with a single pole contactor and bypassing the on motor push button relay.

https://www.clipsal.com/Trade/Produc...1&sg=120641052

Sure we have them at our mens shed for 3Phase gear, buy they are pretty exxy items especially for <10A machine in a DIY situation.

The cheapest solution would be to reposition the DCs NVR to inside the shed and put a $20 Fletty Style RF switch in between the NVR and the DC.

Cheapest option is to bypass the NVR and use the powerpoint switch or a remote. You can hook the remote to a contactor if you're worried about the remote contacts failing.
It's a DC, it's not like there's a spinning blade that can kill you if it turns on unexpectedly after a power outage.
If it's going to turn back on, you were using it when the power failed. It's not exactly a dangerous piece of equipment, unless you're a guinea pig.

Edit : Ill-informed comment removed in the light of BobL’s post following this one.

Originally Posted by NCArcher

Cheapest option is to bypass the NVR and use the powerpoint switch or a remote. You can hook the remote to a contactor if you're worried about the remote contacts failing..

I assumed the DC already has an NVR and wasn't suggesting going out to buy another one. And while you have it, it might as well be used especially if its not going to cost anything.

They may not have a sharp blade but they have a lot of angular momentum so can still do a lot of damage if you get any body parts near the moving impeller. Even a 1HP unit will easily take fingers or a hand off even at low speeds.

Using the power point alone as a switch can lead to problems. I've seen a bloke (bloke 1) come real close to having his fingers/hand taken off with a DC. The old machine had no switch on the machine and bloke 1 had sucked up a rag and jammed the impeller which tripped a breaker. Bloke 1 unplugged the DC and removed the ducting from the front of the DC and stuck his hand into the impeller to remove the rag. 4m where the DC plug is laying on the floor there's a jumble of cable and power points and bloke 2 thinks he's plugged in his machine in but he's actually plugged the DC back in and turned it on. Fortunately bloke 1 already had the rag out but it was seconds away from him having his hand Up the DCs cloaca. Multiple failures all round with this one that has really brought it home to me you cannot be too careful with these suckers.

Originally Posted by Colin62

Even if it turns on while you’ve got your hand up the inlet and are pulling out shavings, both the speed and torque are low enough as it starts that I doubt you’ll do any lasting damage.

Do you want to try it and tell us about it.