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Looking at the controller on the internet the default reverse power alarm is 35KW which would about correspond to your 50 amps. Since it worked at the factory I am assuming that the sensing CTs are part of the generator skid at did not have to be disconnected and then reconnected at sight. I...

I think there are multiple schools of thought here. Paralleling outputs make it easier to see that they are activating at the same time. Additionally if there is a change in the logic that affects both outputs there is only one place to change it. If the logic is repeated in two different...

I am a little confused with your statement “ The val(v)e is fail-to-close so in case of loss of signal or instrument air failure the valve the valve should have been opened.” I have heard of a valve being “fail close” or “fail open” or “air to close” or “air to open”. I ‘m not familiar with...

Although this is an older post, I thought I'd comment as I didn't feel the original question was really covered. If a 24 volt dc system is operated ungrounded, there is often a ground detection system installed. These will have two relatively high impedance relays or other ground detecting loads...

I have No Experience with this, but Note 2 of the drawing states: For DC control connect –ve/0V to terminal 36. -(For negative switch / positive common, refer to RWS indicated). -Control signal threshold voltages: -DC: “on” ≥65Vdc / “off” ≤40Vdc, max 130Vdc. So my guess is yes you need 125...

alagan85, Glad to hear your problem solved, appreciate the feedback. I am curious though, in your original list item 3 said R,S,T and C cores were running healthy. When you rebooted them the last time you waited until one processor was up and healthy before you did the next one. I have a...

Not sure if all Rotorks are the same but i would assume they are similiar. Just looking at a print I found on line the control transformer has a primary fuse (FS1) this could be blown. You'll need to look for the source of the short circuit. There is a 24 volt connection from the power board to...

I have spent a couple of hours looking over my old Mark IV prints (we upgraded to Mark VI many years ago so I dont have ant hardware to look at). I now understand that P28VR is the redundant source of 28 volt power. Based on item 9 on your list you dont appear to have a problem on the positive...

I'm not to familiar with the 28Vdc on the Mark IV. I assume the P28VR is the return of the 28 Vdc and it is ungrounded. I'm not sure what you are using as a reference on your measurement or if your measurement are positive or negative 28 volts. Just be carefull that you don't fool yourself...

120 volts on 500 ohm resistor will draw 28.8 watts (120^2/500). The aux PT will also have the burden of the sync lamp, sync-scope, and whatever the MarkVIe draw would be. We had a similiar set up. As I recall, our AUX PTs were 150 VA. I dont have access to the info any more but sounds...

Not sure if I am understanding the question. I don't think I'd use time. I would just set up an appropriate deadband between the on and off settings. There are a lot of variables to consider such as room size, heater size, air circulation, RTD location. I think it will be a bit of trial and error.

I'm not sure where this discussion is taking place so excuse me for mudding things up but I have gotten confused and would like to interject a question. I am studying the NEC and my understanding is that a continuous duty motor > 1 Hp requires a separate overload device or one integral to the...

The way it was explained to me: The gas turbine is rotating an electromagnet, producing a rotating flux field. The current in the stator is also producing a rotating flux field. The resulting rotating field is the vector sum of the two. The angular difference of the two fields is referred as the...

Looking at the picture a little closer it would indicate 2 phases are pegged past 800 amps while the third phase shows 1114 amps, ~132 KV, MW pegged, and ~ 40 Mvars. This would be about 255MVA which would mean you would be flowing about 251 Mwatts which would explain the Mwatt meter being...

Looking at the pictures the meters are all overloaded. My guess is that the CT is on the 400 amp tap instead of the 800 amp as you think. This would mean the actual current closer to 600 amps instead of 1200. Just a guess on my part.

I keyed on the saturation of the CT without asking an obvious question. Why do you have an 800/1 CT on a circuit pulling 1200 amps. Is the digital meter calibrated correctly. The CT will output 1 amp with 800 amps flowing through it. Is your digital meter calibrated to display 800 amps when 1...

A CT saturation is more dependent on the amount of iron in the CT. You can have a a small 800/1 CT or a large 800/1. The CT develops the voltage to drive the current through a given load or "burden" . Saturation refers to the iron in the CT becoming saturated with flux where it can no longer...

Retired so I don't have any equipment to check this on but as I recall........ ======================================================== Calibration of 2 Element Watt/Var Transmitter Assumption : relay test set available which can provide a single phase current and voltage and control the phase...