Thermal-imaging
1300-4-A-SCAN (*1300 427 226)
  • Home
  • Services
    • Thermal Imaging
    • Power Quality Monitoring
    • Test and Tag
    • RCD Testing
    • Ground Penetrating Radar
    • High Temperature Scanning
  • About Us
    • Quality Control
    • Procedure
    • Infrascan Removes Switchboard Covers
  • Articles
    • Miniature Circuit Breaker (MCB)
    • Thermal Imaging Pyro Cable
    • Thermal Imaging Motor Protection Relays
    • Negligible Faults Can Become Significant
    • Why Should I do Thermal Imaging?
    • Temperature Rise Limits
    • Regulations
  • Gallery
    • Interesting Images
  • Testimonials
  • Certificates of Currency
  • Useful Links
  • Contact Us
    • Sydney
    • Melbourne
CALL US NOW. CLICK HERE.

Is My MCB Not Working Properly?

Marginal Overcurrents:
At mild or marginal over currents it's probably working just fine. The latitude for tripping is pretty wide. See the table below:
Table
Interpretation of Table:
Say you have a 16 amp breaker. Assume a load of 18 amps.
The MCB should either NEVER trip, or trip within 1 hour, so the breaker may function day in day out with no spurious tripping.
If the breaker 'sees' 20 amps, it should trip within 2.5 minutes to 1 hour.
Most electricians have no time or the capacity to thoroughly test the equipment, so if an over-current is detected then breakers are simply replaced to maintain safety standards.
Before a miniature circuit breaker is condemned, check if the MCB is a B, C or D type and compare the current vs tripping curve accordingly.
Click here for a handy link to a MCB data sheet and graphs.
Infrascan Thermal Imaging © 2020 All Rights Reserved
 SEO Services by Logical Assembly