How to diagnose if the heating elements broken and short circuit for glass tempering furnace?

1. How to find if the heater wire broken or not?

Measure the resistance value between the phase wire screw of heater and N row using a low ohm range of an multimeter. If the wire is not burned, the normal resistance value should be less than 10 Ω. If the resistance value is the maximum value, it means that the wire has been burned out. Further inspection can be conducted to determine which section of the wire is broken, and then welding or replace it.

For most glass tempering furnaces, two wires are connected in series and installed in parallel to form a heating zone. The resistance values of the wires in each heating zone should be close to and consistent with each other;

But also, there is some glass tempering furnace is composed of four wires forming a heating zone, which is composed of two wires connected in series and then connected in parallel. At this moment, the measured normal resistance value is only equivalent to the resistance value of one furnace wire. If the resistance value doubles, it means that one of the wires is broken. The wire wiring should be disassembled for further testing to identify the location of the disconnection.

2. How to find if the heater wire short circuit or not?

The possibility of mutual short circuit between the wires is very small, mainly due to the short circuit between the wires and the heating furnace shell, commonly known as "heating wire grounding".

Before testing, please remove all the wires of the N rows of the furnace body and measure the insulation level between the N rows and the furnace shell using a multimeter with a 200K Ω range. When the resistance value is at its maximum, it indicates that all the wires in this section have good insulation to ground. If the resistance value is very small, the furnace wire must be removed from the N row and checked one by one until the short circuit of the furnace wire is detected, and then processed or replaced.