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VFD braking part duex

I tried and failed to get a VFD brake resistor running on my 10EE with a motortronics unit. Turned out this unit doesn't support a brake resistor.

OK, I got a Hitachi SJ200 a sittin on the shelf. So, I put it in today. Turned out to be an awful job - tight quarters. here's the manual:

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ARGH! I got the exact same problem, I'm getting no dynamic braking. I've got two Hitachi SJ100 so I wired the same and programmed the same - the only real parameter change is B90 from 0 to 100 (% dynamic braking usage). The brake resistor measures 35 ohms and is across RB and + terminals. Note: the SJ200 manual has no table of correct brake resistor size but I used 35 ohm on an SJ100 5 hp. like this one.

I'm getting no voltage on the brake resistor during deceleration, not good.

Any suggestions before I waste my money and buy a brand new 5hp. Hitachi SJ100?

Karl

Reply to
Karl Townsend
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Call Hitachi and cry on their shoulder. Perhaps they will take pity and tell you the secret code to get the VFD to use the resistor. Or tell you that your case is beyond hope.

I've got a SJ100 with braking resistor driving the Clausing 5914, and it is not obvious that the braking resistor makes any difference. I have not got around to measuring the voltage across the resistor. I didn't notice the B90 parameter in the manual, so I'll have to look into that.

Joe Gwinn

Reply to
Joseph Gwinn

If all fails, you can buy a 5 HP drive from me, with a brake resistor. (that is 5 HP 3 phase, needs to be derated for single phase).

$100 if you want one in a not so good cosmetic condition (cracked front cover).

I will give you one year right of return, but you pay all shipping.

i
Reply to
Ignoramus22378

I reduced stop time from 9 seconds to .4 seconds on my CHNC lathe with the SJ100

Karl

Reply to
Karl Townsend

Very fair, but I need to drive a 5hp. from single phase.

Karl

Reply to
Karl Townsend

Are you decelerating hard enough and with a big enough workpiece to cause the VFD to dump excess voltage to the resistor?

Just checking...

Mark Rand RTFM

Reply to
Mark Rand

Yes, looks like you need something bigger.

i
Reply to
Ignoramus22378

Same here, about the same reduction on my Bridgeport, when I installed a suitable brake resistor. It feels like "instant soft stop".

i
Reply to
Ignoramus22378

That pretty well cinches it - you don't need fancy instruments to tell

0.4 seconds from 9 seconds.

So I looked - B90 was set to zero, the default, which disables dynamic braking. Set to 100.0%, and set the deacceleration time F03 to 1.0 seconds. What a difference.

I always suspected that I had a settings problem, but never got round to figuring it out. This was the clue.

Joe Gwinn

For the record, I have a 50 Ohm braking resistor, and the 5914 has a 2 HP motor.

Reply to
Joseph Gwinn

Yep, I'm trying to reduce decel time F003. If i go below 10 seconds the drive KOs code 7 which is bus overvolt.

Karl

Reply to
Karl Townsend

Check B095 (dynamic braking control)

The USA default value is 00 (off) (page 3-39 of the manual you linked to)

The other values are 01 (enable during RUN only) and 02 (enable always).

Reply to
JohnB

BINGO!!!

THANKS A BUNCH. Set stop time to 2 seconds, I'll play more tommorrow.

karl

Reply to
Karl Townsend

Reply to
allieb.flaws

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