[
VII
Microprocessor Control ]
- 20 -
HWE20150
GB
Table 2 shows how the field-installed heater is controlled.
Table 3 shows how the time delay is selected.
*1 Time delay can only be selected with MA controller. If use of a non-MA controller is desired, the time delay must first be selected
with the MA controller. Then the non-MA controller can be attached and used.
*2 The default time delay setting is 20 minutes.
*3 Time delays are approximate.
Table.2 [Heater Control Table]
Mode
Change
Condition
EH1 ON
(To -T
RA
) >
2.7 °F [1.5 °C]
AND
T
RA
has not
increased by 0.9 °F
[0.5°C] in X min
EH2 ON
EH1 ON for > 5 min
AND
(To -T
RA
) >
2.7 °F [1.5 °C]
AND
T
RA
has not
increased by 0.9 °F
[0.5°C] in 5 min
EH1 OFF
(To -T
RA
)
≤
0.9 °F [0.5 °C]
EH2 OFF
KEY
• EH1: Electric Heater 1
• EH2: Electric Heater 2
• To: Set point temperature
• T
RA
: Return Air temperature
• X: Time delay (Selectable. Default is 20 min. Selectable to 10, 15, or 25 min)
Table.3 [Time Delay Selection Table]
Function Setting *1
Action *3
108-1
Set Time Delay to 10 minutes
108-2
Set Time Delay to 15 minutes
108-3
Set Time Delay to 20 minutes *2
108-4
Set Time Delay to 25 minutes
