Alternate" Mode - York SUNLINE MagnaDRY DR240 Installation Manual

284811-YIM-C-1008
which engages circuit # 1, resulting in circuit #1 reheat
mode operation.
When the room thermostat calls for first stage cooling,
with or without a call for dehumidification, the RCB
senses a signal through "Y1", de-energizing the HGR,
which de-energizes SOL 3 and SOL 2, and energizes
SOL 1, engaging circuit # 1, resulting in circuit #1 cool-
ing mode operation.
When the room thermostat calls for second stage cool-
ing, the RCB senses a signal through "Y1" & "Y2" and
engages circuit #1 and circuit #2 in the cooling mode.
Indoor blower operation is initiated upon a call for first
stage cooling, second stage cooling or dehumidification.
Anytime there is a call for 2 stages of cooling, the unit
will not operate in the reheat mode, even if there is a
call for dehumidification at "HUM".
The unit will not operate in the reheat mode if there is
any call for heating.
On units with economizers, the unit will not operate in
the reheat mode if there is a call for cooling and the
economizer is operating as first stage of cooling.
All safety devices function as previously described.
56

"ALTERNATE" MODE

When the RCB detects a need for dehumidification
(24VAC) at "HUM" via the field supplied dehumidistat
connected to RHTB-1 and RHTB-2, and there is not a
call for cooling, it energizes the HGR, which energizes
the SOL 3, SOL 2, and de-energizes SOL 1. The unit
then operates with circuit #1 in reheat mode and circuit
#2 in cooling mode.
When the room thermostat calls for first stage cooling
while there is still a call for dehumidification, no
operational change is made. The call for cooling is
ignored and the unit continues to operate with circuit #1
in reheat mode and circuit #2 in cooling mode.
When the room thermostat calls for second stage cool-
ing, the RCB senses a signal through "Y1" & "Y2" and
de-energizes the HGR, which de-energizes SOL 3 and
SOL 2, and energizes SOL 1. Both circuits operate in
the cooling mode.
Indoor blower operation is initiated upon a call for first
stage cooling, second stage cooling or dehumidification.
Anytime there is a call for 2 stages of cooling, the unit
will not operate in the reheat mode, even if there is still
a call for dehumidification at "HUM".
The unit will not operate in the reheat mode if there is
any call for heating.
All safety devices function as previously described.
Johnson Controls Unitary Products