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Soft Starter Voltage Drop

Soft Starter Voltage Drop

Soft Starter Voltage Drop

(OP)
A very basic question on effect of a RVSS on upstream power distribution.

If an across-the-line starter draws 600% FLC, resulting in a voltage drop of 5% on upstream distribution - if we use RVSS and limit start current to 400% - does this mean voltage drop is reduced by 1/3?

I am trying to understand the impact of the RVSS operating at reduced voltage and reduced current - so the actual KVA output from the starter is reduced by more than 1/3. What is the impact on the upstream distribution? I assume upstream distribution sees the full 400% current.

RE: Soft Starter Voltage Drop

Yes, the new voltage drop would be roughly 3.3%. The RVSS operation is a bit of an enigma in that it really just reduces the current.

RE: Soft Starter Voltage Drop

(OP)
In my example, I think he meant that 5% voltage drop would be reduced to 2/3 of 5%, or 3.3%.

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