caosesvida
Senior Member
had a question about motor rating, I have never seen this before. I see RLA< FLA< and now SLA, does anyone know what this is? thanks.
SLA rating on motors
- Thread starter caosesvida
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bphgravity
Senior Member
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- Florida
Re: SLA rating on motors
My guess is "starting load amperes"?
My guess is "starting load amperes"?
caosesvida
Senior Member
Re: SLA rating on motors
i wonder if the starting load amps would be different from locked rotor?
i wonder if the starting load amps would be different from locked rotor?
bphgravity
Senior Member
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- Florida
Re: SLA rating on motors
I would say yes. There will always be an "in-rush" current from a starting motor, even if the rotor and armature is free. I would guess that the RLA would be less than the SLA which would be less than the LRA. (If SLA even means "starting")
I would say yes. There will always be an "in-rush" current from a starting motor, even if the rotor and armature is free. I would guess that the RLA would be less than the SLA which would be less than the LRA. (If SLA even means "starting")
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- Semi-Retired Electrical Engineer
Re: SLA rating on motors
I looked around a bit, and am not sure I found the answer. But I am inclined to believe the "S" word is "stall." I can say that the current a motor draws at the moment of starting is the same current it would draw forever (or until something breaks) if you were to hold the rotor immobile. In other words, there is no difference between "locked rotor amps" and "starting amps," until the motor actually starts moving. The counter-emf created by the rotor, as the rotor moves faster and faster, causes the current drawn from the source to drop. When the motor reaches full speed, presuming it is fully loaded, the current drawn will have dropped down to its "full load amps" value.
If you load a motor further and further beyond its rated output power, it will slow down, thus drawing more and more current. Eventually, you will load it too much, and it will stall. I believe that "SLA" represents the current that it will draw at the stall point.
I was confused for a while about the many ways "SLA" shows up in the context of battery systems. Then I found out that in that context, it means "sealed lead acid."
I looked around a bit, and am not sure I found the answer. But I am inclined to believe the "S" word is "stall." I can say that the current a motor draws at the moment of starting is the same current it would draw forever (or until something breaks) if you were to hold the rotor immobile. In other words, there is no difference between "locked rotor amps" and "starting amps," until the motor actually starts moving. The counter-emf created by the rotor, as the rotor moves faster and faster, causes the current drawn from the source to drop. When the motor reaches full speed, presuming it is fully loaded, the current drawn will have dropped down to its "full load amps" value.
If you load a motor further and further beyond its rated output power, it will slow down, thus drawing more and more current. Eventually, you will load it too much, and it will stall. I believe that "SLA" represents the current that it will draw at the stall point.
I was confused for a while about the many ways "SLA" shows up in the context of battery systems. Then I found out that in that context, it means "sealed lead acid."
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