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ヒートポンプ Blueridge BHP15のPDF 取付説明書をオンラインで閲覧またはダウンロードできます。Blueridge BHP15 11 ページ。 Split system heat pump
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The outdoor unit and indoor blower cycle on demand
from the room thermostat. When the thermostat blower
switch is in the ON position, the indoor blower operates
continuously.
Emergency Heat Function (Room Thermostat)
An emergency heat function is designed into some room
thermostats. This feature is applicable when isolation of
outdoor unit is required or when auxiliary electric heat is
staged by outdoor thermostats. When the room thermostat
is placed in the emergency heat position, the outdoor unit
control circuit is isolated from power and field-provided
relays bypass the outdoor thermostats. An amber indicating
light simultaneously comes on to remind the homeowner
that he is operating in the emergency heat mode.
Emergency heat is usually used during an outdoor unit
shutdown, but it should also be used following a power
outage. If power has been off for over an hour and the
outdoor temperature is below 50°F (10°C). System should
be left in the emergency heat mode at least six hours
to allow the crankcase heater sufficient time to prevent
compressor slugging. This applies only to systems with
crank case heaters.
Defrost System
The defrost system includes two (2) components: a defrost
thermostat and a defrost control.
Defrost Thermostat
The defrost thermostat is located on the outdoor coil of
most models and on the liquid line between the check/
expansion valve and the distributor on R-410A TXV
equipped models. When defrost thermostat senses 29°F
(42 on R-410A TXV's) or cooler, the thermostat contacts
close and send a signal to the defrost control board to start
the defrost timing. It also terminates defrost when the liquid
line warms up to 60°F.
Defrost Control
The defrost control board includes the combined
functions of a time/temperature defrost control, defrost
relay, diagnostic LEDs and terminal strip for field wiring
connections.
The control provides automatic switching from normal
heating operation to defrost mode and back. During
compressor cycle, the control accumulates compressor run
times at 30-, 60-, or 90-minute field-adjustable intervals.
If the defrost thermostat is closed when the selected
compressor run time interval ends (call for defrost), the
defrost relay is energized and defrost begins. The factory
setting is 90 minutes which is the optimum efficiency
setting.
506318-03B
Figure 3. Outdoor Unit Defrost Control Board
Defrost Control Timing Pins
Each timing pin selection provides a different accumulated
compressor run time period for one defrost cycle. This
time period must occur before a defrost cycle is initiated.
The defrost interval can be adjusted to 30 (/T1), 60 (T2),
or 90 (T3) minutes. If the timing selector jumper is not in
place the control defaults to a 90-minute defrost interval.
The maximum defrost period is 14 minutes and cannot be
adjusted.
A TEST option is provided for troubleshooting. The TEST
mode may be started any time the unit is in the heating
mode and the defrost thermostat is closed or jumpered. If
the jumper is in the TEST position at power-up, the control
will ignore the test pins. When the jumper is placed across
the TEST pins for 2 seconds, the control will enter the
defrost mode. If the jumper is removed before an additional
5 second period has elapsed (7 seconds total), the unit will
remain in defrost mode until the defrost thermostat opens
or 14 minutes have passed. If the jumper is not removed
until after the additional 5 second period has elapsed, the
defrost will terminate and the test option will not function
again until the jumper is removed and re-applied.
Time Delay
The timed-off delay is 5 minutes long. The delay help to
protect the compressor from short-cycling in case the
power to the unit is interrupted or a pressure switch opens.
The delay is bypassed by placing the timer select jumper
across the TEST pins for 0.5 seconds.
Pressure Switch Circuit
The defrost control incorporates 2 pressure switch circuits.
The high pressure switch connects to the boards HI PS
terminals. The low pressure switch is factory installed.
Issue 1850
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