Page 10 of 24 / IM 407
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. Unit is factory wired for 230V operation. If 230V power supply is
used, transformer must be rewired by disconnecting the power
from the red transformer primary wire and connecting the power
lead to the orange transformer primary wire. Place an insulation
cap on the red transformer primary wire.
3. Terminal block on Mark IV/AC board provides 24 VAC at termi-
nals R and C. All other terminals are 24 VDC output.
4. All temperature and pressure switches are normally closed.
5. 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 12. Unit sizes 024 through 060 (208-230 volts, three-phase) 060686704 Rev. B
Figure 13. Unit sizes 024 through 060 (460 and 575 volts, three-phase) 060686804 Rev. B
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.