Adjustable Motor starter ampherage setting
I have a motor with 600v 3 phase -- 5 hp -- and I am installing a new motor starter with a built in adjustable overload. The service factor for the motor is 1.25 . What do I set the overload to? FLA?
I was told that motor starters with adjustable amp settings have the 25% higher than FLA amps built in and you adjust the dial to FLA only and not add another 25% above the FLA rating. Is this correct?
Ive been told by some mechanics that I add 25% above the FLA when setting the dial
but I was told by my instructor in school that you only set the dial to FLA as the adjustable overloads have the +25 percent needed built-in.
Which is correct?
Get the info from the Mfg of motor starter!
UA Local 32
Bingo. The manufacturer of the starter has approved overcurrent setting instructions.
Originally Posted by buford
In the code, the general spec is that a motor with a service factor of 1.15 can have its overload device set for no more than 125% of FLA. (430.6 A 2)
Bear in mind for general information....motors that have a service factor greater than 1.0 have that listing for being able to accept the heat of additional loading for transient periods of time. The service factor is not a rating that is indented for continuous load above FLA.
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2 Tim 3:16-17
RSES CMS, HVAC Electrical Specialist
AOP Forum Rules:
My understanding is -- I go to the electrical supplier -- tell them what my FLA is of my motor with my service factor get a motor starter with overload protection -- and then after I read the manual it will tell me if my FLA dial setting includes 25 % or if I have to add 25% to the FLA
Basically yes, the instructions in or with the overload protection will spell this out. Most have this info online.
UA Local 32