Lennox PRODIGY2.0 User Manual

33
6. Dehumidification Operation
Dehumidification mode is a combination of cooling to dehumidify and heating to maintain space temperature.
Supermarket reheat uses gas heat and Humiditrol
®
units route hot discharge gas to a reheat coil downstream of the
evaporator. A gas heat unit is required for Supermarket Reheat and a Humiditrol
®
unit is required for Humiditrol
®
Reheat.
Economizer operation is disabled during dehumidification operation except when dehumidification mode operation -
parameter 105, Option 1 is selected.
NOTE: Dehumidification operations as referenced here are not supported for Energence Ultra-High Efficiency
LCH/LGH036U-74U. See Ultra Dehumidification Operation on page 43.
6.1. Supermarket Reheat Operation Settings
Go to SETTINGS > RTU OPTIONS > EDIT PARAMETER=105 (DEHUMID MODE)
Parameter 105 (Option 0) - No Reheat
Parameter 105 (Option 1) - Supermarket Reheat using de-humidistat (wired thermostat mode only)
IMPORTANT
Supermarket Reheat is allowed on gas/electric units only and not electric/electric units. A de-humidistat will bring on
first-stage cooling to dehumidify and a room thermostat will energize heating to maintain indoor temperature. To disable
free cooling in this mode, select economizer global mode (figure 5) but do not connect the global input (P297-9). An
optional de-humidistat is required. Refer to figure 5.
K55
B
A
K55-1
7
5
2
S86
P297
J297A
1
2
B
3
4
5
6
7
8
C
9
10
R
OCP
C
G
W1
W2
Y1
Y2
24 VAC POWER
A55
TO R
TO G
TO Y1
TO M3 THERMOSTAT INPUTS
ALL OTHER THERMOSTAT
SIGNALS REMAIN CONNECTED
AS SHOWN ON THE RIGHT.
TO PROVIDE DEHUMID SCHEME, USE S86
DEHUMIDISTAT AND K55 RELAY
R
OCP
C
G
W1
W2
Y1
Y2
Figure 5. Dehumidification Diagram (Parameter 105, Option 1)
Parameter 105 (Option 2) — Supermarket Reheat using Relative Humidity Sensor Control
A relative humidity sensor will bring on first-stage cooling based on the set point set with parameter 106 or from the L
Connection network. First-stage cooling will de-energize when relative humidity drops to parameter 106 minus
parameter 107. A wired thermostat or room sensor will energize heating to maintain indoor temperature.
An optional relative humidity sensor is required. Refer to figure 37.
Go to SETTINGS > RTU OPTION > EDIT PARAMETER = 106 (DEHUMID SETPOINT) and 107 (DEHUMID
DEADBAND) (see paragraph 6.3. for further details concerning dehumidification set point)
6.2. Humiditrol Dehumidification Operation — (Humiditrol
®
Reheat)
Go to SETTINGS > RTU OPTIONS > EDIT PARAMETER = 105 (DEHUMID MODE)
A relative humidity sensor reading above set point will energize first-stage compressor(s) and hot gas will be routed to
the reheat coil based on the set point set with parameter 106 or from the L Connection network. The following options
show additional conditions which must be met before reheat will be energized:
Humiditrol dehumidification will de-energize when the relative humidity drops to parameter 106 minus parameter 107.
An optional relative humidity sensor is required. See figure 37.

Lennox PRODIGY2.0 Specifications

General

Brand	Lennox
Model	PRODIGY2.0
Category	Controller
Language	English