Rojek switchgear and the current heatwave.

[Sawyer]

Dear All,

I have a 3 phase Rojek MSP 315 planer/thicknesser, which appears not to like the current hot weather :?

Workshop temperature has soared to 90 F this afternoon. Meanwhile, I've been surfacing a pile of softwood 3x1": so fairly easy work for such a machine
After about half an hour of this, the machine cut out for no obvious reason, but would re-start about a minute later and worked for another few minutes, before cutting out again. If re-started, even when left idling, the machine kept cutting out.

The cutting out became more and more frequent, till I had to stop work. An hour later, all seemed well for a while until the problem started again.

The Rojek manual (predictably enough) has been of no help.

Mechanically, nothing appears amiss. All the electrical line seems fine and no fuses have blown. I also investigated the possibility that the micro-switch may be causing trouble - but apparently not. Someone I know, thinks that the switchgear may have a thermal cutout?

The conclusion seems to be the the machine (like its operator) is suffering from having to work in such heat. Has anybody else ever experienced this and/or, is such a conclusion feasible?

 

[Togalosh]

Hello Sawyer,

It does sound like a temperature issue (as motor overloads need to be manually reset usually)..but I can't see our summers being an issue.[but now I see you are in France ]

The motor might have an integral over temp cut out switch..this may or not be reading the correct temperature & I'm not sure if these are replaceable/repairable (I do not get into motor repairs as it's not economical in my line of work). I have had this issue before where a motor is not under excessive load or 'struggling' yet it cuts out.

You could trace the fault when the machine stops with a multimeter http://www.argos.co.uk/static/Search/se ... IMETER.htm
& see what's what.

If you are getting all 3 phases to the motor but the motor isn't running (& assuming you've not lost the neutral - assuming you have one) then the motor is at fault..if there's no power there then where does it stop - the issue is there.

Hope that helps a bit.

 

[9fingers]

I suggest looking at the motor connection box. There should be 3 heavy leads for the phases and an earth. If there are another two, perhaps thinner wires, this could be a temperature sensor leading back to the NVR
Take off the fan cover from the back of the motor and make sure the fan fins are clean and blow out all dust with compressed air.

My hunch is that the airflow over the fan is impaired and in the hot French weather, the motor is overheating.

HTH

Bob

 

[Sawyer]

Bob, Togolosh, thanks for replying.
It looks as though temperature was indeed the problem. Today was cooler, and workshop temperature about 4-5 degrees C cooler than yesterday. All the stuff I surfaced/edged yesterday, went through the thicknesser without a hitch!
Come on Rojek, I'm sure Czech summers must get pretty darn hot? The machines should be used to it!

 

[9fingers]

All supports my theory of marginal cooling. When did you last blow out dust from the motor?

Bob

 

[Losos]

Come on Rojek, I'm sure Czech summers must get pretty darn hot? The machines should be used to it!

I will confirm that they do get +30 C there, in fact this week SWMBO is telling me it's up to +36 C but that doesn't mean Rojek have allowed for that, as a general rule their machinery is built like a tank but has no refinements so my guess is it's a thermal cut out on the motor which Rojek 'buy in' and no ones complained before.

Send them an e-mail but don't hold your breath waiting for a reply :lol:

 

[custard]

I dug out a portable fan for the bedroom recently when the temperature went up. Switched it on and the blades whizzed, around but the breeze was less than from a bronchitic goat.

Checked the blades and they had a light furring of dust on the leading edge. Cleaned it off and the fan output immediately went from bronchitic goat to wind-tunnel!

Made me realise that it wouldn't take much in the way of dust to render a woodwork machine's cooling fan absolutely useless.