You could send your samples to TjH2B. They have special tests they can run for OLTC's, OCB's and Regulators. The test uses a different set of parameters to diagnose the oil since it will be exposed to arcing.
http://www.tjh2b.com/
Well we finally got our STR system commissioned. We opted to start with a Westinghouse DS-416 breaker software and installed a few cubicle kits to get practice for our upcoming turnaround where we’ll install another dozen or so.
I am extremely impressed with this system. The portability (we...
We also had a false trip on a 12000 HP motor due to GF currents passing on the shields through a GFCT. Event: We had a VAC interupter partially fail on a feeder breaker at our main subsataion. The main sub also supplies power to the starter for the large motor. The result was there was enough...
One of our local sales reps actually brought one to our plant to check out.
First off, at the time the unit was not approved by a NRTL. That is an immediate strike against our company policy. I suspect that reason for it is because it was manufactured in Australia.
Second, we have quite a few...
Thanks Breakerboy.
I have a system controller on order and a couple of kits to try out. While there is a substantial up-front cost. I believe it will be worth it.
We have approximately 200-250 breakers to retrofit so it will take a few years.
Next year we will convert the subs we are...
All of our technicians are instructed to hand crank the breaker to ensure it is inserted correctly, then connect the device and get out of harm's way to operate the RR device.
This particular unit has a torque limiter for the different manufacturer's breakers. It also counts number of turns as well as displaying "real time travel position". There are different transmissions for the different breaker types/ frames.
king 101, how is the quality of the Safe T Rack...
Not all of the instruction books are available on the web. I have had to request one through the website. I took a few days, but was worth it.
They actually mailed me a hardcopy
Does anyone have experience with the remote racking device manufactured by Safe-T-Rack? http://www.safe-t-rack.com/
We are in the process of getting one to our plant to try one out and was looking for some possible pros or cons to the device.
Thanks
The refinery now belongs to someone other than Motiva. It was sold about 4-5 years ago to Premocor, not sure if they still own it.
The two motors were part of a syn-gas plant that started when the place belonged to Texaco.
I nkow they had some process issues for quite a while and couldn't use...
If you want to separate the electrical possibility from mechanical, perform a "coast down" test. Monitor vib and shutdown the motor. At this point electrically induced problems should go away. Any mech problems should remain and degrade as the motor coasts down.
They probably want to bring out the thermistor wires with the motor leads because on LV motors there usually isn't much room to machine another hole in the frame. As long as the rating of the insulation of the PTC thermistor cables are rated for the motor's operating voltage I wouldn't see a...
The phase to ground problems is what started our investigation into the phase to ground unbalances. All motors, MOVs, and other 3 phase loads have been working just fine.
Thanks for the info
David,
I have been working on the exact same problem at our refinery.
Our readings were normal phase to phase (480v) and around 140 L-n, 200 L-n and 400 L-N.
We thought at first we had a transformer problem. So we took the transformer offline and perfromed a megger test and turn to turn ratio...
I have seen some recent installations at 15kV being only a few inches from Phase to ground supported by a piece of glastic/ fiberglass channel.
Be very careful of using any glastic/ fiberglass supports for unshielded cables as the supports need to be sealed on any cut ends to prevent the...
We have installed larger CT's when dealing with multiple/ parallel conductors. Our's were supplied from the manufacturer (Powell Industries). They tand to be twice the size of a "normal" ZSCT.
The motor is approx. 20 years old. It had been 10 years since it was last semt out for reconditioning. We had some reliability issues with the field wiring and motor controls as this job was put in on the cheap. We averaged 4-5 starts per year for the last few years. ~2600 amps for ~15 seconds...
We use IRIS PD monitoring on a 13.8 KV 12,000 HP induction motor and have been sucessful in validating the health of the motor. We were able to monitor the increase in PD and made the decision to have it pulled during our last outage. As it turns out, the coils were moving in the slots, some...
