29
HVAC Mode — LOW HEAT (16)
The unit will be in low heating demand mode using either gas
or electric heat.
HVAC Mode — HIGH HEAT (17)
The unit will be in high heating demand mode using either gas
or electric heat.
HVAC Mode — UNOCC. FREE COOL (18)
In this mode the unit will operate in cooling but will be using the
economizer for free cooling. Entering this mode will depend on
the status of the outside air. The unit can be configured for out-
side air changeover, differential dry bulb changeover, outside air
enthalpy changeover, differential enthalpy changeover, or a cus-
tom arrangement of enthalpy/dewpoint and dry bulb. See the
Economizer section on page 60 for further details.
HVAC Mode — FIRE SHUT DOWN (19)
The unit has been stopped due to a fire shutdown input (FSD)
or two or more of the fire control modes, purge, evacuation, or
pressurization have been requested simultaneously.
HVAC Mode — PRESSURIZATION (20)
The unit is in the special fire pressurization mode where the
supply fan is on, the economizer damper is open and the power
exhaust fans are off. This mode is started by the Fire Pressur-
ization (
PRES
) input which can be found in the
INPUT
FIRE
sub-menu.
HVAC Mode — EVACUATION (21)
The unit is in the special Fire Evacuation mode where the sup-
ply fan is off, the economizer damper is closed and the power
exhaust fans are on. This mode is started by the Fire Evacua-
tion (
EVAC
) input which can be found in the
INPUT
FIRE
sub-menu.
HVAC Mode — SMOKE PURGE (22)
The unit is in the special Fire Purge mode where the supply fan
is on, the economizer damper is open and the power exhaust
fans are on. This mode is started by the Fire Evacuation
(
PURG
) input which can be found in the
INPUT
FIRE
sub-
menu.
HVAC Mode — COOLING DEHUM (23)
The unit is operating in Dehumidification mode. On the units
configured for Humidi-MiZer operation, this is the Humidi-
MiZer dehumidification mode (subcooling).
HVAC Mode — VENTING DEHUM (24)
The unit is operating in reheat mode. On units configured for
Humidi-MiZer operation, this is the Humidi-MiZer reheat
mode.
HVAC Mode — HEATING DEHUM (25)
In this mode the Heating Control Point HEATCPNT = 85°F.
Only Staged Gas heat can be used in this mode, by itself, or
supplemental to Humidi-MiZer. A third-party heating source
may be activated during all 3 dehumidification modes, with the
use of the ALRM relay. See “Auxiliary Relay Configuration
(AUX.R)” on page 33 for more details.
Summary of Contents for WEATHERMAKER 48A2020
Page 112: ...112 Fig 20 Typical Main Control Box Wiring Schematic 48 50A Units ...
Page 113: ...113 Fig 21 Typical Auxiliary Control Box Wiring Schematic ...
Page 114: ...114 Fig 22 Typical 2 Stage Gas Heat Wiring Schematic Size 060 Units Shown ...
Page 115: ...115 Fig 23 Typical Staged Gas Heat Wiring Schematic Size 060 Units Shown TO NEXT PAGE ...
Page 116: ...116 Fig 23 Typical Staged Gas Heat Wiring Schematic Size 060 Units Shown cont ...
Page 117: ...117 Fig 24 Typical Electric Heat Control Schematic 50 Series Size 060 Units Shown ...
Page 118: ...118 Fig 25 Typical Controls Option Wiring Schematic SW1 SW2 OR DEHUMIDIFY SWITCH ...
Page 119: ...119 Fig 26 Typical Power Schematic 48 50A2 A3 A4 A5 060 Unit Shown ...
Page 120: ...120 Fig 27 Typical Power Schematic of Greenspeed Low Ambient Option 48 50A 060 Unit Shown ...
Page 121: ...121 Fig 28 Typical Small Chassis Component Location Size 020 035 Units ...
Page 122: ...122 Fig 29 Typical Large Chassis Component Locations Size 040 060 Units ...
Page 185: ...185 APPENDIX C VFD INFORMATION cont Fig F Internal Enclosure Fan Replacement A48 7716 ...