We are planning a new project at one of our Refinery. Select Gate-1 approval is in process and we are to move forward for Gate-2 & Gate-3 approval. One of our requirement is that of Bench Marking of our Project before the final investment approval is put to the Board for Approval. In this...
In one of our newly commissioned plants we have a motor Motor ( rating 415 V,2.2 KW,4.3 Amps, 1455 rpm).This motor is powered through VFD ( V/f control ). The normal operating range for the motor was 265 to 1465 rpm . However for meeting the process requirement , the motor is required to be run...
What is electric efficiency and thermal efficiency for a gas engine ? If power output is given , how to calculate the fuel consumption ? Which efficiency will come in the calculation, electric or thermal ?
For our installation , we are planning a common emergency DG set (EDG) of 2000 KVA , 415 volts. However there is one location with anticipated requirement of 200 KVA which is approximately 2 km distance from the EDG. The location and the logistics do not allow a separate EDG set of 200 KVA to be...
Thanks everyone for your replies.
Going by the '3 times KVA' rule , 6 MW generation capacity should be sufficient (not allowing for voltage drops)for starting the motor.However we are considering the option of soft starter.
We are planning a captive power generation of approximately 18 MW ( 3 x 6 MW gas engine driven generators). Can we go for a 1600 KW DOL start motor ? What is the correleation between the generator capacity and the maximum permissible rating of motor for DOL start ?Is there anything we can take...
In such a case, my first doubt would be the polarities of CT connections for the particular feeder. Normally this would be identified if a 'stability test' had been carried out for all the feeders at the time of commissioning of the switchboard/ differential protection . If it is possible to...
Just continuing with this, another practice that I have seen is that no overhead cable trays are allowed inside the process units .All the cables to the equipments are brought through the cable trench (filled with sand)only.In fact , if a new cable is to be laid when the unit is in operation ,it...
Thanks @davidbeach for your reply.However the practice that I have seen in our refinery is that for cable trenches that pass through process units , the whole trench is filled with sand just after the cable laying is completed .I prezumed was that it must be related to probable hazard that a...
As I understand , for directly buried cables , a layer of sand is provided before laying , and another layer is provided after laying for protection. However if I lay the cable inside underground concrete cable trench on cable trays , is it still required to fill the cable trench with sand. Does...
For our newly installed induction motor , the cable size used is 3C x 95 sq mm ( PVC , Armoured) , whereas the gland (double compression) size is higher ( suitable for 3C x 120 sq mm) . As a result there is a slight gap between the cable and the gland. Does this effect the Ex d protection of the...
In my opinion you can power up the VFDs with certain precautions. Capacitor replacement can come later.In any case, for the VFDs it is recommended to replace the capacitors after a period of around 7 years.
However before you power up ensure that the insides of the VFDs are thoroughly cleaned...
