Typically the CT's are mounted so that power flows into the polarity side first and towards the load.
On LVCB's that have smaller CT's they can be mounted on the Line Side in the same physical direction,and they will have the same polarity.
The reason that yours is different is due to the size...
Hi EECougar:
You stated,
"We actually have a CT going to a relay but the relay is reading zero amps and zero degrees so we are thinking that a shorting screw was left in place somewhere."
Depending on the type of relay, don't forget to check the case. Over the course of time I have found...
Hi eleceng01:
Try this website:
www.electricalmanuals.net
They have some old equipment manuals on this site, there are no CO type relays listed under Westinghouse, but most of them are listed under ABB.
Good Luck.
Ang
Hi Pawdge:
I found a pretty good source for old equipment manuals recently. I believe you can find what you are looking for at www.electricalmanuals.net.
I saw a DH & DHP Maintenance Manual that has some mech. drawings that were pretty good. The document number is NP-7410.
Good Luck.
I like the pacer tracer by amprobe. I also use the scotch trak by 3m.
The quality of the tracer is important in situations such as yours.
Most tracers have an adjustment on the receiver so that you can turn the setting down as low as possible to ensure that the only signal that gives a...
Hi Proznick;
I am in total agreement with the group and Old Field Guy couln't have said it better.
I too come from the field and find test switches an absolute necessity.
As stated earlier you can prurchase the type that have "see-thru" covers, you can label each...
Hi JBD:
In your earlier post you did not state that the problem was following the relay. The relay settings appear to be proper for the load, possibly a little higher than necessary.
I suspect you have a faulty relay,and not a CT issue. Can you provide some additional information?
1. What is...
Hi JBD:
You may have a CT wiring issue or a CT Burden issue for the (3) CT's that are wired to the IFC relays.
I would check all of the CT secondary connections in this circuit. I would also test the CT's for ratio, polarity and saturation. Perhaps one of the CT's is breaking...
Hi HiSet:
I have never seen a trip coil on a fuse unit assembly for 22 kv applications. I do not believe what you are inquiring about is possible.
Is there an upstream switching device that can be modified for this application?
Good Luck.
Ang
Hi climb 1:
I am of the opinion that you have a defective bushing. Do you have a composite or a porcelin type bushing? You are not supposed to use alcohol on the composite type.
Has any other electrical testing been performed besides Power Factor, Contact Resistance and Dew...
Hi Powercrazy:
jghrist is absolutely correct. The abbreviations you listed are standard abbreviations for single ratio, dual ratio and multiratio C.T's.
Good Luck.
ANG
Hi Rockman 7892:
I agree with slavag I would check the settings of this relay and confirm the CT specs and wiring. You may have a rolled CT, but more likely the additional load is exceeding the relay set points during inrush.
I would test the following:
1. SEL relay for proper pick-up at...
Hi Farmape:
I agree with Zogzog it is better to keep your cables energized with no load on them. If you shut MV cables down for long periods of time you should test them before re-energizing.
The exterior surface of load break and dead break elbows is not designed with conductive or...
Hi Powerwagon75:
I have been considering this problem and I agree their may be a power suply issue, but I would like to mention some other considerations:
1. You mention that this installation is wired for Residual Ground Fault sensing.
a) Has the Neutral CT wiring connections been checked...
raghun:
Sorry for the delayed reply, I was occupied on a project. with regards to when the cable should placed into service:
I personally would prefer that the cable pass a jacket test and then at the very least a Hi-potential test prior to the soak test. If you now the parameters (length...
