Continuous Heating Mode Control - Mitsubishi Electric PURY-P200YLM-A(1) Service Handbook

[5-2 Outdoor Unit Control ]
5-2-8

Continuous heating mode control

(1) Continuous heating mode start conditions
Continuous heating mode will start when all the conditions listed in the table below are met (outside temperature, cumulative
compressor operation time, and piping temperature).
However, even when the condition is met, if the Continuous heating mode is performed the maximum of 3 times consecutively,
the reverse defrost operation will be performed once the next time.
SW4 (848) must be set to ON to perform Continuous heating mode.
Outside tempera- 2.0°C [35.6°F] to 3.5°C[38.3°F]
ture (TH7)
Cumulative com- When 20 minutes have passed
pressor operation
time
Piping tempera-
ture (TH6)
(2) Valve operation during Continuous heating cycle
1) When Single unit
Continuous heating mode is performed in the order shown below.
For a single unit, defrosting is split between the upper heat exchanger and lower heat exchanger with P200 to P400 models
and EP200 to EP350 models, and between the left heat exchanger and right heat exchanger with P450 to P500 and EP400
to EP500 models. Each operation is performed as shown in the table below.
Outdoor unit fan 1
Outdoor unit fan 2
SV1a
SV5b
SV9
SV10
SV11
SV4a
SV4b
SV4c
SV4d
SV7(EP200-EP500 models
only)
21S4a
21S4b
HWE1314A
Single unit
TH6>TH7−8°C [14°F]
P200-P400, EP200-EP350 models
Bottom HEX in de-
frost cycle
In operation
-
OFF
ON
OFF
OFF
ON
ON
OFF
-
OFF
ON
ON
-
3.5°C [38.3°F] to 7.0°C[44.6°F]
When 30 minutes have passed
TH6>TH7−8°C [14°F]
P450-P500, EP400-EP500 models
Top HEX in defrost Right HEX in defrost
cycle
In operation In operation
OFF
ON
OFF
OFF
ON
OFF
ON
- 141 -
Combination units
-5.0°C [23.0°F] to 7.0°C[44.6°F]
When 20 minutes have passed
TH6>TH7−6°C [18°F]
Left HEX in defrost
cycle cycle
Stopped
Stopped Stopped
OFF
ON
OFF ON
OFF ON
ON OFF
ON OFF
ON OFF
OFF ON
OFF OFF
ON ON
ON
ON
GB