What temperature causes the ATS48 to have the Over Heating Fault (OHF) state?


12 July 2022

What can cause an Over Heating Fault (OHF) state on ATS48?

Product Line:
ATS48 series soft starters.

All models

fault condition

OHF is triggered in the ATS48 series starters when the heat sink temperature rises above 95 degrees Centigrade (203 degrees Fahrenheit).

Procedures for remedy
* Check the mechanism (wear, mechanical play, lubrication, blockages, etc.).
* Check the sizing of the starter-motor in relation to the mechanical requirement.
* Check the operation of the fan (if the ATS48 used has one), ensuring that the air passage is not obstructed in any way and the heat sink is clean. Ensure that the mounting recommendations are observed.
* Wait for the ATS48 to cool before restarting.

If the temperature is too cold below the Soft starter's environmental specifications, it will trip on OHF.
For open type ATS48 the temperature ranges are:
For Operation:  
14 to +104*F (-10*C to +40*C) without derating
Up to +140 *F (+60 *C), derate the current by 2% for each *C above 40 *C
14 to 122 *F (-10*C to +50 *C) with user provided shorting/bypass contactor.
For Storage:  -13 to +158 *F (-25 to +70 *C)

For the enclosed units the temperature ranges are:
For Operation:
Ambient conditions in installed area from 0 to 40 *C, 32 to 104 *F (Type 1 and 12); 0 to 50 *C, 32 to 122 *F (Type 3R)
For Storage: -25 to +70 *C, -13 to 158 *F