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Circuit Breakers Theory Testing and Commissioning Chapter | 7 95
FIGURE 7.10 Trip circuit of circuit breaker.
FIGURE 7.11 Microohmmeter test connection for a CB contact resistance test.
resistance calculated. In many instruments will indicate a reading directly in
micro-ohms as shown in Fig. 7.11.
The obtained values should be compared with factory test reports or the
manufacturer’s claimed values.
7.6.2 Insulation Resistance Testing
The test voltage should be between the phase to earth and across the poles,
by measuring each phase to earth (or body) and across the pole for each
phase.
