Danfoss TT400 Series User Manual

Page 98 of 108
M-AP-001-EN Rev. N
M-AP-001-EN Rev. N
Installation
20.6.2 Circuit Grounding Improper grounding or voltage in circuits connected to the compressor I/O board can lead
to component failures. In particular, the interlock and analog output circuits are sensitive to
improperly connected external circuits (see Figure 20-7).
Prior to connecting the control wiring to the compressor I/O board, check for improper
grounding. Improper grounding can be identied by measuring the voltage between the
customer’s negative terminals and the ground (J1 COM or Modbus shield) terminal on the
compressor I/O board (see Figure 20-7). If the measured voltage is not zero, determine
the source of the voltage. The most likely cause of voltage is insucient insulation of the
external circuit. In case of uncertainty of the grounding, connect the negative terminals of
the external circuit to a ground and then connect the external ground to the ground on the
compressor I/O board.
Figure 20-7 - Interlock and
Motor Speed Connections

Danfoss TT400 Series Specifications

General

Brand	Danfoss
Model	TT400 Series
Category	Compressor
Language	English