Harmony Series 2 Homelift - XH00200 Issue: D Page 46 of 106
Up/Down Control and Control Mechanism Circuit Functional Description
When an Up call is placed, the signal is input into the CE966 Mains Control Board on the Up
pin of connector of TB5. If the UpHold signal is present, the CE966 responds with a latched
output signal of +12V on the UpSig ping of TB5.
This 12V signal is connected to the CE1652 Voltage Inverter board (Grey Wire) where it is
converted to approx 5.3V. This voltage is output on the Upsig in pin (Pink Wire) and
transported up the trailing cable to the FNLUP pin of TB12 of the CE1654 PCB. This
provides an input to the safety circuit logic of the CCE1654 board and ensures that a down
call cannot be initiated when the lift is travelling upwards.
When an Down call is placed, the signal is input into the CE966 board on the Down pin
connector of TB5. If the DnHold signal is present, the CE966 responds with a latched output
signal of +12V on the DnSig pin of TB5.
This 12V signal is connected to the CE1652 board (Blue Wire) where it is converted to
approx 5.3V. This voltage is output on the Upsig in pin (Green Wire) and transported up the
trailing cable to the FNLDN pin of TB12 of the CE1654 PCB. This provides an input to the
safety circuit logic of the CCE1654 board and ensures that a down call cannot be initiated
when the lift is travelling upwards.
The Blue potentiometer on the CE1654 PCB located at position VR5 controls the creep and
dump system. The output voltage on TB7 8V1 pin is set using this potentiometer to between
8.1 and 8.2Vdc.
When the lift is at the upper level the control mechanism is enabled and the CE1654 board
can receive and action either a creep or dump signal should they be input on TB8.
On receipt of a Creep signal. The CE1654 board responds by outputting 5.35V (Typical) on
the FNLUP pin of TB12. This voltage travels down the trailing cable to the CE1652 board
where it is converted to +12V and inputs to the CE966 on the UPSIG pin. The hydraulic
pump will then activate until this signal is lost.
On receipt of a Dump signal. The CE1654 board responds by outputting 5.35V (Typical) on
the FNLDN pin of TB12. This voltage travels down the trailing cable to the CE1652 board
where it is converted to +12V and inputs to the CE966 on the UPSIG pin. The hydraulic
solenoid will then activate until this signal is lost.
If for any reason the voltage on the FNLUP or FNLDN should exceed 8.2V (e.g. due to a
potential failure of the trailing cable) then the protection circuitry on the CE1652 board will
cause the associated 500mA fuse on the board to fail. This effectively disables the levelling
system of the lift, and protects the voltage inverters on the Ce1652 board from being
damaged.
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