ABB ACH580-01 - Guidelines for Installing the Drive to a TT System

Note: These are the EMC filter and varistor screws and their materials in different drive
frame sizes.
Ground-to-phase varistor screwsEMC filter screwsFrame size
Metal VARPlastic EMC (DC)R1…R3
Metal VARPlastic EMC (DC), plastic EMC (AC)R4…R9
￭ Guidelines for installing the drive to a TT system
The drive can be installed to a TT system under these conditions:
1. Residual current device has been installed in the supply system.
2. EMC filter screws have been disconnected (= they are plastic screws or there is no
screw). Otherwise EMC filter leakage current will cause the residual current device
to trip. For R1…R3, the VAR screw must be plastic, and for R4…R9, the VAR screw
must be metal.
Ground-to-phase varistor screwEMC filter screwsFrame
size
Plastic VAR (remove metal VAR screw)Plastic EMC (DC)R1…R3
Metal VARPlastic EMC (DC), plastic EMC (AC)R4…R9
Drive
N
L3
L2
L1
Note:
• ABB does not guarantee the EMC category because the EMC filter screws have
been disconnected.
• ABB does not guarantee the functioning of the ground leakage detector built inside
the drive.
• In large systems the residual current device can trip without a real reason.
168 Electrical installation – North America