Specific Fault Diagnosis For Cc875 ‘E’ Units; No Led's Lit Or Flashing - Marstair CC 875 Technical Manual

SPECIFIC FAULT DIAGNOSIS FOR CC875 'E' UNITS
A fully electronic system comprising CC875 'E' with MHPUE or DCUE communicates between the units by digital codes. Signals are
transmitted every 10 seconds, therefore a delay of up to 10 seconds could occur before the system responds to a command. Similarly if
the communication link is broken, the outdoor unit will shut down within 15 seconds. To reset: Switch the mains off to both indoor and
outdoor units to reset the microprocessor; the current programme is retained in the indoor pcb memory.
Check for alarms i.e.
i Audible alarm or LEDs flashing - see below
If NO external connections are made to alarm terminal 5, the presence of an alarm condition can be checked for by testing continuity
ii between L and 5; Alarm = 220ohms, Clear = open circuit. WARNING: All parts of the circuit are at high voltage, if any external
connections are made to terminal 5, the continuity meter will be damaged
The outdoor unit can be forced to operate for test purposes by temporarily linking live directly to terminal 3
(up to 20 seconds delay)
Outdoor unit runs continually at
L
high speed
If all external devices appear O.K. the pcb may need to be replaced
M No LED's lit or flashing
Regular audible pulsed signal -
N
all LED's lit
Indoor unit continues after
O
stop/off command
Unit will not respond to infrared
P commands.
No audible answer signal
Unit answers infrared
Q commands
with double audible signal
Sounder beeps and LED(s) flash
R
0.5s ON, 0.5s OFF
All LED's lit and continuous
S
audible signal
T Short cycles between cool and
heat
HANDSET: If the handset fails to respond to button operations, disconnect and then reconnect the battery.
The previous programme state is retained in the memory.
LED STATUS AND ALARM INDICATIONS
Status display
Alarm indications
Tel: 01823 665660
Heronhill - for all your Marstair requirements
Charge link JP6 still fitted
MHPUE in heating
Minimum speed adjustment set too high
No mains supply or internal fuse blown
Fan motor plug disconnected
Motor internal thermal protector operated
Ribbon cable to fascia not connected
Receiver pcb fault
Indoor temperature sensor problem
Outdoor sensor problem
Overrun of 30 seconds in heating
Handset not plugged into wall bracket (if
appropriate). Fault in connections between wall
bracket and indoor unit
Battery discharged
Operating in charge mode
Communications not yet established. Wait 2
minutes from power up
Demanded mode not available
Warning of alarm status
Microprocessor fault
System oversized for room
LED Flash Rate ON/OFF
(seconds)
Red Amber Green
C
F
D
C
0.5 / 5.0
C
0.5 / 15
C
2 x 0.5 / 15
C
0.5 / 0.5
F
0.5 / 0.5
D
0.5 / 0.5
C F
0.5 / 0.5
C D
0.5 / 0.5
C F D
0.5 / 0.5
F D
0.5 / 0.5
C F D
www.heronhill.co.uk
Remove JP6 charge link
Normal
Reset minimum speed
Check electrical supply and fuses
Reconnect fan motor plug
Check motor and rectify
Reconnect
Check circuit board and replace
Disconnect data link to identify which unit, if
fault clears it is outdoor unit
Replace outdoor unit sensor
NORMAL
Plug in correctly and check connections
Replace battery
Remove charge link from outdoor unit
If electric heater is known to be fitted, double
signal indicates open circuit element or thermal
protector
Double signal in response to on/off command
indicates under time control
Details below
Replace indoor unit pcb assembly
Use cool or heat programmes NOT 'Auto' and
set to lower speed
Sounder
ON OFF In Operation
ON OFF Heating Demand
ON OFF Cooling Demand
OFF Standby
OFF Clock Controlled Standby
OFF Setback
OFF Filter Clean Advisable
BEEPS Network Warning
BEEPS High Condensate Level
BEEPS Low Pressure Warning
BEEPS High Pressure Warning
BEEPS Contactor Overload Operated
BEEPS Outdoor Fan Fail
ON BEEPS Sensor Fault
68
Condition Status
Normal
Normal
Normal
Normal
Normal
Normal
Normal
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Fax: 01823 665807