Hello mr Ryan how do i know what size braker should be at the control cabinet.. is that braker size also 600% .. of motor lock current... I was looking a pump it has main 600 amps and braker at motor control cabinet is 225amps Thanks for your videos
Most 3 phase 480 motor contractors use 115 to pull in the contractor.... so we are dealing with 2 different voltages here. Correct?? 15 % for Coil voltage , 5 % for mortar voltage?? This almost seems backwards to me in that as long as the contractor pulls in without chattering, the motor will turn on a fairly reduced voltage.... may be a dumb question but I’m curious enough to risk it!❤
He really meant contactor, not contractor. And you really meant motor not mortar. Of course, a motor has a rotating magnetic field. A solenoid doesn’t.
If a fire pump motor had a 15% voltage drop the 120 volt control circuit would be close to that ( depending on length of wire from fire pump control panel to motor ) . Years ago Allen Bradley used to supply think they called it the seal contactor voltage.( big name for lowest voltage that a starter will pull in without chattering ). Several times I have came across plain Jane NEMA motors feed by 208 volts while motor starter had a 240 VAC coil. During the day have measured the 208 at load side of starters to be 196 volts. ( over a 17% voltage drop ). 120 volt control circuits a lot safer for people working on equipment.
Well….the issue is that the 115VAC panel shown is a diesel fire pump controller. A contactor is used in a higher voltage electric motor driven fire pump.
Excellent summary and review. The photo, however, is of a diesel fire pump controller. The voltage drop is meant for electric fire pump controllers. Diesel fire pump controllers start the engines with DC batteries, and the 115 VAC shown there is only used to charge those batteries, so voltage drop wouldn't apply here.
Hello mr Ryan how do i know what size braker should be at the control cabinet.. is that braker size also 600% .. of motor lock current...
I was looking a pump it has main 600 amps and braker at motor control cabinet is 225amps
Thanks for your videos
Most 3 phase 480 motor contractors use 115 to pull in the contractor.... so we are dealing with 2 different voltages here. Correct?? 15 % for Coil voltage , 5 % for mortar voltage?? This almost seems backwards to me in that as long as the contractor pulls in without chattering, the motor will turn on a fairly reduced voltage.... may be a dumb question but I’m curious enough to risk it!❤
He really meant contactor, not contractor.
And you really meant motor not mortar.
Of course, a motor has a rotating magnetic field. A solenoid doesn’t.
If a fire pump motor had a 15% voltage drop the 120 volt control circuit would be close to that ( depending on length of wire from fire pump control panel to motor ) . Years ago Allen Bradley used to supply think they called it the seal contactor voltage.( big name for lowest voltage that a starter will pull in without chattering ). Several times I have came across plain Jane NEMA motors feed by 208 volts while motor starter had a 240 VAC coil. During the day have measured the 208 at load side of starters to be 196 volts. ( over a 17% voltage drop ). 120 volt control circuits a lot safer for people working on equipment.
@@denverbraughler3948 thanks denverbraughler!! Frickin spell check☹️
Well….the issue is that the 115VAC panel shown is a diesel fire pump controller.
A contactor is used in a higher voltage electric motor driven fire pump.
He addresses that regardless…
The paragraphs deal with the contactor….VD across that…
Excellent summary and review. The photo, however, is of a diesel fire pump controller. The voltage drop is meant for electric fire pump controllers. Diesel fire pump controllers start the engines with DC batteries, and the 115 VAC shown there is only used to charge those batteries, so voltage drop wouldn't apply here.