Typically where do the Thermographic inspection windows for MV (Medium Voltage) switchgear are installed; on the front door of the circuit breaker (CB) compartment or on the door of the cable compartment? What are the pros and cons of installing a thermographic window on the front door of the CB...
What determines the choice of excitation in low-voltage versus medium-voltage generators—specifically, PMG or AREP/auxiliary winding?
I've observed that AREP/auxiliary winding excitation is commonly used in low-voltage diesel engine generators, while PMG is typically preferred for...
Hello Mr. Che Kuan Yau,
Thank you for your response!
After discussing with my client, I confirmed that the clause "no (test supply) disconnections are required when the unit is in the test position" applies to certain vendors who are unable to provide a separate control power (via the sliding...
Online monitoring refers to tests conducted while the motor or generator is in operation.
Offline monitoring is performed when the machine is not operating.
I came across a spec "Continuous monitoring of stator field winding insulation during the generator is offline shall be provided".
You...
All outgoing units shall be executed as fully withdrawable units complete with test facilities, i.e. all connections to vertical busbars and outgoing power and control cables shall be via plug/sockets/sliding contacts and no (test supply) disconnections are required when the unit is to be put...
a) If the system operates as a single-pass (non-recirculating) setup, the temperature rise can be "unrestricted", constrained only by the flow rate, pressure, and the heat exchanger's material limits. Is my understanding correct?
b) From API 541 - How does specifying the minimum temperature rise...
We need to install light fixtures in an area expected to be submerged for approximately two weeks each year. We have chosen fixtures rated for both IP66 and IP68.
Would standard XLPE, armored cables be sufficient for this application, or should we consider specialized cables for these conditions?
Another question is whether there will be any issues with the stop push button (local or remote). For instance, if I have implemented a time delay in the circuit during the transition period, when the operator presses the stop push button (either local or remote), do they need to push it down...
I’m considering using this type of capacitor trip device or an off-delay timer to maintain the transition period. However, since this is a motor circuit, it may also delay the trip on actual fault. The ACB has a Micrologic electronic trip unit; my question is whether the Micrologic unit...
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I came across an old discussion thread here,
where it mentions that the maximum allowable outlet temperature (API 541) is 49°C. Does this imply that the cold primary coolant (air) temperature is approximately 56°C, which seems significantly higher than the typical ambient temperature of...
Steam is generated from the boiler using the dual fuel (mgo & burning Voc (volatile organic compounds) when the cargo is loaded into the tanker. Depending on the heat value of the VOC gases generated from the cargo loading operation, excess steam shall be used to drive a steam turbine...
I understand the concept of temperature rise in windings, but I’m unsure about the temperature rise in a generator’s cooling system. There are two key temperatures involved: the cooling fluid’s inlet and outlet temperatures. The difference between them is the temperature rise of the coolant.
My...
Yes, that's how it should be, but here undervoltage release is solely used for Emergency shut down purposes (fail safe), not for monitoring the undervoltage . however since being a motor feeder, the breaker to be tripped on the 690V undervoltage or deadbus. Therefore, this feeder should have...
Hi Mr. Che Kuan Yau,
Thank you for your reply,
1. The control power is of 230V AC fed by 230V AC UPS distribution boards
2. The ESD relay, K2 (SIL 3 rated) is of 24VDC - always energized - when deenergized - the contacts of K2 de-energises the undervoltage release (MN); which inturn trips the...
We have three diesel generators (3.5 MW) that need to operate in parallel with a 1.5 MW steam turbine generator (STG) on a tanker. Since the STG manufacturer already has the unit ready off the shelf, and management has decided to use it (long lead item). I understand that since the STG has...
Actually the control circuit power to the MCC is fed from the UPS distribution board A and UPS distribution board B with automatic transfer happening in the MCC. (see the drawing below),