Slightly OT: 24V brake contactor selection

[Ken Roach]

I need a little sanity check and hopefully advice from some experienced users.

I have a mechanism that we're driving with a JVL MAC3000 integrated servo motor. It has a nice ProfiNet interface to an S7-1500, and the MAC00-EP4 network daughtercard includes a network-controllable or servo-controllable output, but it can only supply 15 mA.

I also have to provide a brake on one of the stubs of the gearbox we're driving. Our mechanical designers have selected one with a 24V brake coil. The only other technical information is that the coil resistance is 30 ohms.

https://www.mikipulley-us.com/bxr-16-10-p-30.html

OK, I=V/R so it will pull about 0.8 A. I know I need a DC snubber in parallel with the brake coil.

What sort of relay or contactor is appropriate for switching an inductive DC load like this ? Could I use a tiny 700-HL solid state terminal block relay, since it says it has a DC rating of 2.0 A ?

 

[kamenges]

If this isn't mission critical and you can live with a slower brake set time I would feel comfortable with the 700-HL solution. Just make sure you have a diode across the brake coil and I think you will be good.

Keith

 

[GaryS]

They don't say is the coil voltage is 24VAC or 24VDC
I don't know why they don't say but I would assume it's DC
if it's DC then you just need a flyback diode across the coil. It will limit the collapsing field voltage to less than 1 V, I use them all the time
as for the supplying the power you just need a 2 amp or higher rated relay

 

[James Mcquade]

Ken,

we use a lot of servos with brakes. they go up/down or in/out.
what we have is the drive power connected to a reversing motor starter rated for the job with with a set of auxiliary contacts powering the brake module.
Seimens and Allen Bradley with no issues. sorry, someone cut a cable on the production line, gotta run.
hope this helps, james

 

[drbitboy]

sorry, someone cut a cable on the production line, gotta run.

run toward it or away from it ?