teco drive and vfd e-stop

hello.

how can i use emergency stop relay(pilz) on teco drive (part number:jsda75a3)?
is it allowable to use a contactor in front of the drive (or even vfd drives)
in order to disconnect 3 phase(r,s,t) after pressing e-stop button?

please tell me about standard way of stopping motor(about when
disconnect contactor and "servo on" contact).

best regards.

E-stop on VFD's is an especially difficult issue due to the large amount of stored energy contained in the drive. If you, for example, apply your estop relay in the input power, the motor could easily run on for 15-30 seconds on the stored energy.

If you put the estop relay in the motor leads and interrupt the power under heavy current conditions, you have major flash issues and potential damage to the drive's output IGBT's.

My suggestion would be to analyze carefully just what you want to have happen when the estop is activated. Is it simply coast to stop, maximum braking to stop, just de-energize the motor for safety purposes? And, to further complicate things, some government jurisdictions dictate how this is to be done and their method is sometimes not very well thought out.

For me, as a general rule, I prefer to design the system so, upon estop activation, the drive remains powered up, current limit regenerative braking is applied, and after motor-load stop is confirmed, remove the input power from the drive. That won't do for some situations but generally, that's the way to get stopped fastest and then de-energized. About the only improvement I can think of would be the addition of a safety brake on the backside of the motor.

hello.

i want to do following tasks:

upon pressing emergency stop button setpoint to drive became zero and disconnect servo on signal with help of immediate contact of e-stop relay(pilz) and use off-delayed contact of e-stop relay for disconnecting contactor between drive and motor.

is it a right way to do or not?

best regards.

you can use an emergency stop safety relay with time delay so, you got the motor comletely stopped then cut the main power to the drive

adel1961 said:

...you got the motor comletely stopped then cut the main power to the drive

Click to expand...

There seem to be different schools of thought on this. I rarely cut the main (line side) power to a VFD or servo drive. Many drive manuals I've read warn against cutting the line power too often. (I recently started a thread about the reasoning for this.) By using a safety relay with delay-off contacts, you can cut the load side after the drive ramps down and there is no current flowing to the motor.

Another benefit of the load side cutout is that some servo drives I've used take upwards of 30-45 seconds to boot up after a power cycle. Doesn't mesh well with an operator that thinks he can be up and running again within 5 seconds of hitting the E-stop.

seee, re-read my post. Remember, taking the speed reference to zero does not mean that the actual speed has gone to zero. I would think you would want the actual speed to go to zero before you start opening any contacts.

kolyur, you are exactly right on powering down a VFD. The power up process is very stressful to the electronics so, if e-stop is going to be a frequent thing, cutting input power is probably not a good idea. Unfortunately, in some jurisdictions, you will have no choice.