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[How do I?] Huanyang for-rev saga


Registered Member
Hi all. I have searched and read every thread out there regarding how to wire for-rev switch to a VFD.
I cant get my head around how to.. I want to use my apron microswitches and I need your help.

My vfd is the well known Huanyang thingy. I have attached a photo of the switch and the connector bridge in
the VFD.
I am familiar with programming theses things but this wiring saga puzzles me.
Can someone please help me explain what wire should go where from switch to vfd?

This lathe is a 12x36 as Grizzly, Enco and others sell.

Thanks in advance.


Ulma Doctor

Infinitely Curious
Active Member
Hi Sharps,
the wiring will go to the top terminal strip pictured in photo #1
locate the DCM terminal, this is the power out supplied by the inverter to power the control circuit.
the DCM power will be attached to the common terminals on both the forward and reverse switches respectively
you'll add a wire from the FWD terminal on the top terminal strip and connect it to the normally open terminal of the microswitch
then, you'll then add a wire from the REV terminal on the top terminal strip, and connect it to the normally open terminal of the reverse microswitch
(you'll need to change PD001 to 1 if you already have not made the parameter change)
i hope the information is helpful :)


Registered Member
Btw..I wanted to mount a braking resistor just in case. The manual says pin P and N. But I dont have them, do anyone now where
to connect it?


Active User
H-M Supporter-Premium
The braking resistor connections may vary by model. The connections on this model are P+ and PR, but this does not indicate that the braking resistor will actually work, many of the HY VFDs are missing the braking circuity even though the terminals are there. Another reason why I do not use these VFDs in most circumstances. I also do not recommend direct connections to the spindle switch, as the machine will auto start when powered up, the E-Stop should be connected in series with the control connections (DCM), but if released the machine would also restart.

Added: The braking wires are there, the switching circuity is not. There was a discussion of this in this forum several years ago.
VFD wiring.jpg
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