Application

Stationary and moving contacts are built from alloys that are formulated to endure the stresses of electrical arcing. However, if contacts are not maintained on a regular basis, their electrical resistance builds up due to repeated arcing, resulting in a significant decrease in the contact’s ability to carry current and an increase in resistance. Excessive corrosion of contacts is detrimental to the breaker’s performance. Hence to check contacts, apply DC and measure the contact resistance or voltage drop across the closed contacts. The use of a higher current value gives more reliable results than using lower current values. The resistance value is usually measured in micro ohms (μΩ).

PCRM-100SM is specially used to measure static contact resistance of LV, HV, EHV circuit breaker contacts installed in energized switchyards. High accuracy and repeatability make it a reliable tool for quality assurance and easy operations. It is a very handy tool for quick maintenance checks in various industries.

Typical resistance measurement applications are: 

Circuit Breaker contact resistance 
Bus bar joints 
Isolator contacts 
Weld joints 
Bond resistance

Features

• 100A true DC test current 
• Resistance range: 0.1µΩ to 2mΩ 
• Direct mV drop reading 
• Internal memory of 100 test
• Dual grounding facility 
• Lightweight & portable
• Rust removing C clamp