McQuay FDD Series

IM 407 / Page 11 of 24
50 Cycle Wiring Diagrams — Mark IV/AC Units
Figure 14. Unit sizes 007 through 012 (230 volts, single-phase) 061415316 Rev. A
Notes:
1. Mark IV/AC controller board contains a static sensitive micropro-
cessor. Proper grounding of field service personnel is required or
damage to controller may result.
2. Terminal block on Mark IV/AC board provides 24 VAC at termi-
nals R and C. All other terminals are 24 VDC output.
3. All temperature and pressure switches are normally closed.
4. Field supplied relays attached to the 24 volt terminals R, W, Y or
G may introduce electrical noise. Never install relays in series
with the inputs.
Notes:
1. Mark IV/AC controller board contains a static sensitive micropro-
cessor. Proper grounding of field service personnel is required or
damage to controller may result.
2. Terminal block on Mark IV/AC board provides 24 VAC at termi-
nals R and C. All other terminals are 24 VDC output.
3. All temperature and pressure switches are normally closed.
4. Field supplied relays attached to the 24 volt terminals R, W, Y or
G may introduce electrical noise. Never install relays in series
with the inputs.
Figure 15. Unit sizes 015 through 019 (230 volts, single-phase) 061415318 Rev. A