[Amps] NTC thermistors as soft start

[Conrad PA5Y]

I have just acquired a GS35B PSU. It is 3 phase and the schematics show 3 x NTC thermistors in series with each primary. I presume that these are some kind of soft start. I am not familiar with these devices but they make me uncomfortable, I have always used a series resistor that is shunted by a relay after a few seconds in the past. I do not have the model number of the devices used as I will need to open the PSU to find out what they are but I assume that they are similar to this device. 

http://www.ametherm.com/datasheetspdf/MS325R020.pdf

The resistance varies depending on the load current and they get hot in order to operate, this really puts me off. They have quite a long time constant so I am uneasy about them altogether. 

Should I be concerned and replacing them with a soft start for each phase? 

Apart from that the PSU is very nicely made and will provide up to 1.6A@ 3600V. 

Regards 

Conrad PA5Y