Last week during tuning adjustments of our DCS system, the GE/Multilin 369 relay reported trip instead of start inhibit. Note that there was no overload during the trip. Our operations personnel doubted the repeat-start inhibit was activated during a second re-start attempt during DCS “tuning”...
We are doing the commissioning of a direct online starter (DOL) 4.16kV, 778HP, 60Hz. medium voltage motor being used for a reaction furnace air blower. The airflow is controlled by a sensor which is upstream of the blower. The motor is tripping recently due to overload. Motor FLA=93.9A, LRA=564A...
I am involved in a substation design for an additional facility of an industrial plant, one of the requirements of the project is to design a grounding grid of the substation. The outdoor transformer is 10/12.5MVA, 13.8kV/4.16kV, DYn1, secondary neutral grounding resistor rated at 400A for 10...
One (1) vertical section of each bus of my existing MV switchgear, 4000A, 13.8kV, 60Hz. is to be modified to replaced the old air blast MV circuit breaker with new VCB. Since the CT's of the existing relays device 50/51 and 50G with zero sequence CT are under rated, we opted them to be removed...
What is the purpose of a PMS GPS clock? If it is required, what are the parameters to be considered?
We will design the electrical system of an additional complex in an existing facility. The PMS will supervise, control and monitor the operation of HV/LV X'formers, switchgears, MCC's, and UPS...
