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60 Cycle Wiring Diagrams — Mark IV/AC Units
Figure 8. Unit sizes 007 through 012 (208-230, 265 volts, single-phase) 060686404 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. 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.
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 9. Unit size 015 (208-230, 265 volts, single-phase) 060856804 Rev. A