View Full Version : Delta Variable Frequency Drive VFDB series - (for the spindle motor)

Fri 02 June 2006, 06:22
A question to kick off this topic....

The MO1, MO2, MO3 multifunction photocoupler outputs of the Delta VFD-B can surely drive Solid State Relays (SSR's) directly....

I have some Crydom D2W202F SSR's. Input spec is 3-32VDC, 1500 ohm, typical input current 3 mA, turns on at 3VDC, turns off at 1VDC.

The Delta Manual says max output 48V DC, 50mA. Could I drive those Crydoms from it? Would I need a "dropping" resistor? (about 4k7 ?)

Mike Richards
Fri 02 June 2006, 08:18

Page 2-23 in the VFD-B manual shows a better connection diagram than page 2-14. It looks like the M01, M02, and M03 share a common ground (MCM). It also looks like they SINK current. To make things really simple, I would connect 5VDC to one side of a 1/4 watt resistor, either 330 ohm or 470 ohm (either would work well). The other side of the resistor would be connected to the + (positive) control input on the Crydom SSR. The - (negative) control input of the Crydom would be connected to M01, M02 or M03. The MCM on the VFD would be connected to the 5vdc supply's GROUND. When the M01, M02 or M03 is turned on, it will SINK some current through the Crydom SSR, thus turning on the Crydom's internal photo diode, which will activate the SSR. Whatever is connected to the 'business' side of the SSR will do its job.

Most SSRs that I've used drop about 1 volt, or so, across the internal photo diode, so a 330 ohm or 470 ohm 1/4-watt resistor gives you about 10ma to 12ma of current without producing too much heat.

After posting, I looked at page 2-12 one more time. It looks like the outputs are already assigned a default use by the factory. Since I'm not in my shop, I can't look at my unit, but I would imagine that you would just disconnect and tape off any wire that is connected to the M01, M02, or M03 outputs.

Fri 02 June 2006, 10:54
Hi Mike, thanks for looking at this. My manual (both original and downloaded pdf) only has 2 pages in Chapter 2, while Chap. 3 has 17 pages. I can't find the diagrams you mention. But I do now understand the sink situation. Thanks.

Mike Richards
Fri 02 June 2006, 11:44
I found the manual at http://www.delta.com.tw/product/em/ac_motor/ac_motor_manual.asp

(My manual is tucked away inside the Alpha's door pocket so I won't loose it - which means that it's easier to read the manual on-line than it is to crawl under the machine to fetch the paper manual.)

Fri 02 June 2006, 13:41
That's a later edition - October 2005. Yes, much better pictures and descriptions all over the manual about other things too. Thanks!

Sun 23 November 2008, 12:45
How far should line reactors be mounted from the control box and Shielded Cables? Can I mount the reactor direct to the base table or control box? How much heat does line reactors generate?


Gerald D
Sun 23 November 2008, 13:13
Good questions Koning, but I don't actually know the answers . . .

For a start, the VFD should preferably be outside the "bob" control box - maybe in a box of its own to keep it clean if the shop is very dusty. The line reactor would be close to the VFD and thus away from the control box.

Here the Reactor is in the blue bracket behind the VFD:

The bracket is open top & bottom for air to convect through.

However, that VFD does collect too much dust (then its speed control goes wonky) and Sean is now going to enclose the VFD and reactor in a separate box. Together with the ferrite rings on input and output.

If one is going for a pair of boxes, then the question arises whether the toroid transformer should move into the VFD box . . . . . .

Robert M
Mon 24 November 2008, 09:54
Hi Guys,
Though this can help (http://www.ab.com/drives/techpapers/Line%20Reactors%20and%20AC%20Drives1.pdf)clarify some questions for those who are wondering what is a line reactor... :confused:
Just to keep the in line with the How to ask questions the smart way (http://www.mechmate.com/forums/showthread.php?t=1108) .
Amicalement, Robert ;)

Tue 25 November 2008, 11:08
Thank you Gerald
with regards to the magnetic field created by the transformer.....I dont know, seems to be working fine for you over the past years and also your reactor is close to the other equipment, I am going to mount the reactor on the inside of one leg halfway down with prevention method of dust build-up ontop of the reactor.
In this working environment is dust a problem and should be part of regular maintenance.
Enjoy the day