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6155049
"Service" test mode
(cont.)
2. T – testing the power module
The parameter "T" allows manual control of the power module. Use a terminal ammeter to assess operation
of the power module and measure the phase current.
a) T = 0 – no triac is connected.
Valid phase currents should be close to 0. Possible values for current consumption are generated by
operating the DHW circulation pump and supplying the control units (low values).
b) T = 5 – a single triac is switched on. Only phase L1 is connected to the heating unit.
Valid phase currents should be close to 0. In the event of a fault with a triac connected to the other
phases, the power consumption increases significantly (high value). In this case, the power module must
be replaced.
c) T = 7 – a single triac is switched on. Only phase L2 is connected to the heating unit.
Valid phase currents should be close to 0. In the event of a fault with a triac connected to the other
phases, the power consumption increases significantly (high value). In this case, the power module must
be replaced.
d) T = T1 + T2 [G1] – switch on an individual heating element [GX] for full power.
The parameter [X] (from 1 to 6) indicates the number of connected heating elements.
Valid current values should be present:
Boiler 8 kW – 5.3 A per phase and heating element
Boiler 24 kW – 9.2 A per phase and heating element
The actual current values depend on the input voltage and the actual resistance of the heating elements.
If the current values for the individual heating elements differ significantly, this indicates a faulty power
module. The power module must then be replaced. If the electrical installation is not equipped with an RCD,
the heating assembly may be damaged (opening of the insulation resistance in the heating element). The
insulation resistance of the heating element must be checked. The heating assembly must be replaced.
If the electrical installation is equipped with an RCD, connecting the mains power supply to the damaged
heating assembly immediately switches off the current. The heating assembly must be replaced.
3. Tin, Tout – Tin, Tout – displays the flow and return temperature values.
Both values should be within realistic ranges that match current conditions. Incorrect measurements or no
display of the temperature value means that the relevant sensor is damaged. The respective temperature
sensor must be replaced.
4. Z3D – CO, manual control of the three-way valve setting for DHW.
Allows valve function to be tested. If the valve servomotor does not respond to parameter changes, check the
fuse on the MSK.80 PCB (1 A) and the input voltage between N and the mains power connector.
CO – correct voltage at terminal LA 230 VAC
CWU – correct voltage at terminal LB 230 VAC
If the servomotor does not respond to changes in the function settings, the servomotor in the three-way valve
has been damaged. The servomotor or three-way valve must be replaced.
Installation sequence
