voltage is insufficient 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
20.6.3 Voltage-Free Contacts
Prior to connecting the interlock terminals of the compressor I/O board, measure the resistance across the
customer’s interlock terminals (refer to Figure 20-8 Interlock Circuit Tests). Ensure that the interlock contacts are
closed. The measured value should be less than 1Ω.
Page 120 of 136 - M-AP-001-EN Rev. S 9/8/2021