NGR, NER Monitor 2

[slavag]

Dear All.
Im locking for NGR, NER Monitor.
Im found such devices at the Straco site, but it only for high resistance/impedance systems with low ground current. What about low impedance? We have something on the market?
Anyone have experience with such monitors?

Thanks in advance.
Best Regards.
Slava

 

[busbar]

To me, low-impedance grounding components are intended to be strictly low duty cycle, with typical protection/monitoring using a CT at the grounded terminal, with one or two inverse-time overcurrent relays for breaker tripping.

I will be interested to hear other opinions about this.

 

[rbulsara]

That is what I would think, low impedance grounding is intended for tripping the breaker after all yet limiting the ground fault current and resultant damage.

Rafiq Bulsara

http://www.srengineersct.com

 

[slavag]

Thanks for reply.
Im sorry, I see now, my Q was not correct.
Of course, busbar, Rafiq you are right.
I saied about NGR damages monitor, not about ground fault monitor .
some monitor of... maybe Ohm's , connections-some kind of on-line monitor.
I hope,Im more clear noe :-(.

Best Regards.
Slava

 

[lansford]

The relay on the Neutral Ground should also be protecting the resistor. And pick up should be less than the continuous current rating of the resistor which is very low for say a 10 second rated resitor. So is a damage monitor needed?
Jim

 

[rbulsara]

slavag:

Do you mean to monitor integrity or condition of the resistor itself? Like to know if it is deteriorating/ degrading overtime? Is that what you mean?



Rafiq Bulsara

http://www.srengineersct.com

 

[slavag]

Hi.
Yes, Rafiq, you understood me right.
Landsford, you are right too.

I don't know, maybe we don't need such devices..don't know.

Best Regards.
Slava

 

[rbulsara]

slavag:
At least that is cleared up. Although I have not heard of or employed such a monitoring device, perhaps someone has.

Just a thought that modern multifunctional relays may be set to check for and alarm much lower current (as additional function), but I never looked at them with that in mind.



Rafiq Bulsara

http://www.srengineersct.com

 

[slavag]

Hi.
Thanks a lot to all.
If no..no problem.
Best Regards.
Slava

 

[timithye]

I had a sales person from Littelfuse in a couple of weeks ago and he indicated they may make something similar to what you are looking for. The Model # from the manual indicates either the PGM-8134 or PGM-8125.

Hope this helps

 

[slavag]

Thanks a lot timithye .
It's other devices, but exactly what Im looking for.

BTW, it seems as STARCO devices.
OK, from here, I will ask directly to STARCO or Littlefuse.

Best Regards.
Slava

 

[rob46]

Please review the attachment.

Best regards.