User manual

GMC-I Messtechnik GmbH 33
Insulation Resistance Measurement in Different Types of Systems
TN–S
• With or without consumer
•N – PE, separately
TN–C
• With or without consumer
• N – PE, together
TT
• With or without consumer
3-phase current (switched at all poles)
Attention:
– Open the overcurrent protective device
– Disconnect the N conductor
– Jumper the L and N conductors
– Insulation measurement between L conductors and N to PE
– Device switch can be open – if single-pole
In the distributor: individual and combined measurements