Heater Control - McQuay MDS Series Service Manual

2.4 Heater Control

There is an optional heater for MDS indoor unit. However, this option is only applicable for ducted model (using
wired controller) and it will function during heating cycle or fan mode. (Please refer to page 48 for dipswitch
2
setting on heater application). User can choose to install one or two heaters. The control algorithm of the heaters
is shown below:
1 Heater
When the set temperature (T
turned ON.
When the set temperature (T
turned OFF.
2 Heater
Heater 1
When the set temperature (T
turned ON.
When the set temperature (T
turned OFF.
Heater 2
When the set temperature (T
turned ON.
When the set temperature (T
turned OFF.
12
-1 T 0.5
s
) is higher than room temperature (T
s
(Ts - Tr > 0.5)
) is lower than room temperature (T
s
(Ts - Tr < -1)
-1 -0.5 T 0.5
s
) is higher than room temperature (T
s
(Ts - Tr > 0.5)
) is lower than room temperature (T
s
(Ts - Tr < -0.5)
) is higher than room temperature (T
s
(Ts - Tr > 1)
) is lower than room temperature (T
s
(Ts - Tr < -1)
T
r
) by 0.5° C, the heater will be
r
) by 1° C, the heater will be
r
T
r
1
) by 0.5° C, the heater will be
r
) by 0.5° C, the heater will be
r
) by 1° C, the heater will be
r
) by 1° C, the heater will be
r
Service Manual SM-MDS_(ii)