Hatachi WJ200-22SF and a external 24v power supply

[jbobb1]

So, because I need to use a 24v external power, is following the connection directly to the vfd per chapter 4-14 the way it's being done, or is there a different route I should be going?

Jim

 

[mksj]

Yes, you would connect the external 24VDC supply per page 4-14 of the manual depending on if you are sinking or sourcing the inputs. Is there a reason where you need an external power supply? There are a few things to be followed, one is the diode when sinking, and the other is any noise or voltage spikes if the external power supply is used to power anything else. If the same power supply is used to power relays or contactors, when the coil is released it can put a reverse voltage spike of around 150V and burn out other components if you do not use reverse diodes across the coils. Other issues can be be electrical noise giving false signaling. In most cases I use the WJ200 internal power supply which is 24VDC @100mA and power separate relays/contactors via a separate 24V power supply.

 

[jbobb1]

The external power supply is for the cooling fan I'm going to be using. I've been reading and following your guidelines, and due to the size of my enclosure, you recommend using one.
My concern was exceeding the VFD max current because I'll have the 4 pole relay and both illuminated power button and E-stop.

 

[mksj]

You are fine if the bulbs are LED, they draw about 9mA and the relay is 70mA, you can draw up to about 100 mA it will overload at around 125 mA so there is some wiggle room. If you use incandescent bulbs they draw too much power for the internal power supply.

 

[jbobb1]

Thanks for that info. I obviously calculated wrong. Bulbs are LED. Time to move forward!
I appreciate all the help.