N0VUSUN and Mitsubishi-D700-SC

[Doddy]

i have noticed that the led on the relay lights up but dim and does not click in when the spindle is switched on in mach 3
the relay works 100% if i wire it direct to the power supply it clicks in and closes the contacts.
the relay is wired direct to the +24v on the power supply and the ov ground from the power sully goes to crd on the novusun...the out1 from the s axis goes to the relay for the OV

Good, this is very useful. The relay you have (MY4N-J) is a 24VDC relay, to answer Clive. That the LED on the relay illuminates, dimly, when "on" answers the question of whether the driver is configured correctly - from memory the driver is a very simple thing that doesn't really respect the ports/pins settings in Mach3. So that looks good. You've tried manually energising the relay and that works as expected - so VFD wiring and settings are good. This leads me back to my questions, and a hunch that I have.

First one - photos of the relay, I wanted to check if you've wired the diode correctly, but if you hadn't then you wouldn't be able to manually energise the relay (not without blowing the 1n4001... not entirely unlikely if it is wired the wrong way around).

Secondly, the voltage on the out-1 pin on the NVEM. If it is low, at 0V or maybe up to 2-3V then I'd say the opto-coupler output (internal to the NVEM) is switching as designed. But that would give you a bright LED. If, as I'd rambled about earlier, it doesn't switch effectively (low CTR) then the opto-coupler driving the NVEM output will have a high resistance, and the terminal voltage at OUT1 will be some proportion of the 24V supply. The higher the terminal voltage, the lower the voltage across the coil (and the internal LED) and the less energy to switch the relay. My question of the measured voltage - if above more than a few volts then I don't believe the NVEM is effectively switching the relay and we have to look at a current amplifier. I (or many others here) can help you sort that.