Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations MintJulep on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  • Users: paliha
  • Content: Threads
  • Order by date
  1. paliha

    Earth switch in incomer

    I have seen earth switch (ES) on the 33kV incomer cubicle of the switchgear. It may be a requirement for the supply authority to ensure no power will be fed back during maintenance etc. My question is how to provide interlock to ensure the ES will not be operated while incoming supply is...
  2. paliha

    Data communication using GSM network

    My object is data transfer between three pump stations and central SCADA station using GSM network. I came across SINAUT MICRO SC - software together with GSM Modem MD-720-3 which i feel is very close to my expectations. What i am not sure is, whether static IP will be required for the...
  3. paliha

    Communication betweem different PLC

    Hi, I am involved with a project where information from an existing PLC is to be taken for the purpose of monitoring by a SCADA system. Basic information are indicated below, Existing PLC - Siemens SIMATIC Application - Filter control of a water treatment plant Initially we planed for using...
  4. paliha

    High capacity raw water pumps - Submersible or vertical shaft driven pumps

    Hi all, Decision between submersible and vertical turbine pumps for raw water pumps has been discussed under thread 407-233951. But my problem is more towards high capacity end in the region of 1250 L/S at 40M. (750kW) Decision is almost made in favor of vertical shaft driven pumps, mainly...
  5. paliha

    VFD Driven motor efficiency

    Hi Friends, I have a question regarding the overall efficiency of VFD Driven motors. Normally the VFD efficiency is around 96% and motor efficiency around 94% (around 30kW range). When we made a measurement for a motor used in pumping system, the overall efficiency fell much below the...
  6. paliha

    Variable Frequency Drives- Wiring diagrams

    I have a problem with selecting between available variable speed dive wiring diagrams especially the location of the main contactor, as indicated below, 1) No contactor- drive is between the feeder MCCB and the motor. This is the simplest. 2) After the feeder MCCB before the VFD- Has the...
  7. paliha

    Use of shunt trip for earth fault protection

    I have come across many earth fault protection arrangements, where the shunt trip of the MCCB along with an earth fault relay is used to isolate a circuit with earth fault. This arrangement is not fail safe for the following, 1) Power supply for the micro relay / earth fault / shunt trip is...
  8. paliha

    VFD Prices

    We need the prices of variable frequency drives (Altivar-61) in the range of 160 kW to 300kW. Is there a list price available some where for this?
  9. paliha

    Lightning surge through power line

    Dear friends, I have a lightning surge problem affecting my circuit. The circuit is a simple 12V relay driven by BC547 transistor. The free wheeling diode is 1N4148. It is certain that the filure is due to lightning surges through power line. The regulator (7812) fails. The transistor)BC547)...
  10. paliha

    stored energy motor operating mechanisms

    When testing a motor control centre, i came across a stored energy motor operator (ABB ISDAO for S6-57 or some thing like that) The closing operation is instantaneous after applying signal on "close" input. The open operation takes plase after few seconds of "open"input signal as there is no...
  11. paliha

    3.3kv substation

    I have a few MCC's each driving a few 3.3kV motors. (total 1200kW load) A 11kV /3.3kV substation is to be constructed a 3.3kV distribution panel is to be designed for this. There is a choise to be made for the substation transformer secondary whether to go for (1) star with neutral solidly...

Part and Inventory Search

Back
Top