Goals and Symptoms

What is the derating factor used when sizing LH4N for a high number of starts per hour than the standard spec of 360 seconds.

Facts and Changes

LH4N Starts/hour
starting

Causes and Fixes

There is not studies which gives a factor to determine the power of LH4 in an application with high number start/stop per hour upper her electrical characteristics of the product.
The catalogue tell you :
-'' if starting and stopping conditions are severe, or if the starting current must be controlled, it is preferable to use an ATS48 unit''.
- ''beyond this starting duty, the start unit must be derated by one size''.

However , we thinks when the number of start/stop is considerable and it would have been preferable to use a variable speed drive.

Note:  The LH4 softstart family is obsolete. It was replaced by the ATS01 softstart, or in the case of the larger LH4's the ATS22.