Novus - Field Logger Power Supply Blown! (and smoking)

Thread Starter


Joined Jan 27, 2022
Hi everyone.

Hoping someone can help.
I have a device called a (Brand: NOVUS) [Model: FIELDLOGGER]
It is a type of multi function logger used to connect and log various devices such as RS485, digital inputs and analogues like temp, and send the signals to a modbus over TCP.

We have had a few units die, no power at all.

SO on investigation I found a 47ohm resistor and a S14K275 Varistor on the 240volt input (looks like providing volt-drop / surge protection), the resistor was open circuit, I changed these and got a nice puff of smoke from the 47 resistor.

The PSU is a sub-board that stands off the main board, which converts the 240volt supply to a multi voltage output of 25/9/11/5 volts

I have checked all the basics, bridge rec seems OK, caps and diodes also OK.

and I got the limit of my knowledge.. if anyone could point me in the right direction of what else to check, it would be really helpful.

Its worth noting it works in a power plant type environment, so the 240 supply would be classed as 'poor'