Page 1 of 1

Soft start option for fans.

PostPosted: Mon Aug 02, 2021 2:49 am
by TrophyBurro
Hi guys I have some fans that start very hight around 40 amps .
Is there a way to set a softstart? They will operate at around 15amps and was hoping to use a single
20 amp output . Not sure if we will have problems at the intitial 40 amp spike

Re: Soft start option for fans.

PostPosted: Mon Aug 02, 2021 10:35 am
by adrian
The PDM doesn't have soft start functionality, however it is designed for devices with a high inrush current. If the continuous current is only 15A then a single 20A output should run it fine.

If you have a look at page 34 of the PDM User Manual it gives you details on how to calculate the trip time for a given current and current limit setting (the value you put in the output configuration). A quick calculation for 40A on a 20A output gives about 10 seconds before tripping. Significantly longer than any inrush would last for.