Hour meter

[Rangeraleg]

Want to install hour meter on PM933VT milling machine. Thought maybe terminals on pc board powered when motor runs. ,but can't use motor leads because frequency varies. THANKS

 

[tq60]

Get a relay to interface.

Look for an output that can be used or relay from motor wires.

Relay controls timer.

Sent from my SM-G781V using Tapatalk

 

[Bi11Hudson]

You're thinking in the right direction, just back up a little. I don't know your machine, but many of the small mills have a switch on the speed pot so the machine always starts slow. Lacking that, use the On/Off switch. A good place to look for a switched lead is to trace the center tab from the fuse holder. Follow that through any switch, then attach a 120 Volt hourmeter. The switch may be ahead of the fuse. Any 120 Volt line that is switched should work. Any neutral will do, from the line cord follow the white wire to a common tie point. Inside the control cabinet, with it's short runs, pairing the two wires doesn't buy you anything. Finding a place to mount the meter will be the biggest problem. If you need to use an external mounting, be sure to use an enclosure rated for line voltage, and the pass through hole is smooth.

You should have a multi-meter, make sure the wires used are switched 120 Volt AC leads. Machine time is the same as On time. The spindle doesn't need to be turning. 120 Volt hourmeters are common, be sure not to use a low voltage or DC type. There is DC in the machine, usually PWM (Pulse Width Modulation) for a small machine. That DC signal has a very high switched frequency and is NOT suitable for anything but the motor. It may well will be higher voltage than the line.

The machine must be powered on when the cabinet is opened. Be sure to unplug it before reaching in for any more than a voltage measurement. Electricity is dangerous, that is well known. Be sure to have a clear work surface when the controls are opened. For a novice, even 32 Volts can put you down. Be sure to have a way to lay the front panel down so nothing touches.

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[mksj]

Probably none of the above apply to the what I am assuming is the PM-833TV (there is no 933VT). It uses a basic VFD/Electronic drive which as far as I can tell has no external programming feature nor does it have output relay/switch that could be configured to switch on with a run command. The VFD run forward/reverse commands use low voltage DC to activate the respective input. The easiest solution is to replace the current 3 position single gang run selector switch with a dual gang. Use the 2nd gang to turn on the hour meter when the selector switch (ON-OFF-ON) is in the forward or reverse position (output wires t the hour meter are connected in parallel) which go to the meter. Hour meters come in different configurations, so on my compressor I have a separate fused 240 VAC line that operates the hour meter via the pressure switch. Why one would want an hour meter on this type of mill which has no time sensitive parts is a bigger question, what purpose doe it serve?

Most programmable VFD's have internal time counters that give the total on time and the run time, as they have serviceable items like the Fan and capacitors that may need to be changed usually after 6-7000 hours of run time. This is more applicable in a 24/7 operating environment and unlikely to be reached in a light duty use environment.

 

[Rangeraleg]

Get a relay to interface.

Look for an output that can be used or relay from motor wires.

Relay controls timer.

Sent from my SM-G781V using Tapatalk

Thanks for posting no relays videos

 

[Rangeraleg]

Thanks for posting no relays VFD