Vertiv | Liebert PEX4 | User Manual
77
General Maintenance
4.8. Electrical Heater
The electrical heater includes three temperature switches that are connected serially to the control loop,
whereas two of the switches are reset automatically, the remaining one is a manual reset switch.
shows a schematic representation of the three switches inside an electrical heater.
No.
Description
No.
Description
1
Manual reset temp switch
3
Auto reset temp switch
2
Auto reset temp switch
Figure 4-2 PTC Electrical Reheater
The following steps need to be followed during inspection and maintenance of the electric heater:
1. Check the electrical heater for rust. Use an iron brush to remove the rust, if possible, or replace it if the
rustiness is immense or if there is some damage.
2.
When heating is required, but heating is not effective, or no heating effect is observed, a multimeter should
be used to check whether the cable connected to the temperature switch is functioning correctly to ensure
that the three temperature switches are normal.
3. If the cable is not functioning properly, remove the electrical heater and check if the manual reset switch
is disconnected. Next, check the automatic reset switches or the electric heater pipe for damage or faulty
condition.
Before exercising the corresponding operation, ensure that the power supply has been switched off.
