The Belt Motor Starts With Delay - Technogym Forma Service Maintenance Manual

6.5. THE BELT MOTOR STARTS WITH DELAY

The problem is caused by the inverter failing to receive the enable signal (Start) or the speed signal.
Replace the inverter
Follow the procedure step by step to correctly diagnose the problem. Take particular care with the
checks highlighted by circled numbers, which are described in detail below:
(1) To check the Start signal, place a tester between pins 6 (signal) and 12 (ground) of connector
K4 on the CPU board. The measured voltage should be 0.2 Vdc when the tread-belt is
stopped, and 4.8 Vdc immediately after pressing the "Start" key.
To check the PWM signal, place a tester between pins 4 (signal) and 12 (ground) of connector
K4 on the CPU board. The measured voltage should be 5 Vdc when the tread-belt is stopped,
whereas immediately after pressing the "Start" key the reading should rapidly decrease until it
reaches a fixed value corresponding to the selected speed. The variation of the signal should
be accompanied by a corresponding variation in the tread-belt speed: see Table 6.6-1 or Table
6.6-2 depending on whether the machine is a Forma 2 or a Forma 3.
(2) To check the Start signal, place a tester between pin 2 (signal) and 1 (ground) of connector J5
on the driver board. When the tread-belt is stopped the reading should be -23.8 Vdc, and
immediately after pressing the "Start" key it should be 0 Vdc.
To check analog speed reference signal, place a tester between pin 5 (signal) and 6 (ground) of
connector J5 on the driver board. When the tread-belt is stopped the reading should be 0 Vdc,
and immediately after pressing the "Start" key the value should increase rapidly to reach a
fixed value corresponding to the selected speed. The variation of the signal should be
accompanied by a corresponding variation in the tread-belt speed: see Table 6.6-1 or Table
6.6-2 depending on whether the machine is a Forma 2 or a Forma 3.
Page 6.24
THE BELT MOTOR
DOES NOT START OR
STARTS WITH DELAY
Are the Start and PWM
signals correct at the
output of the CPU board?
YES
Are the Start signal and the
analog speed reference
signal correct at the output
of the driver board?
FORMA: Service & Maintenance manual - rev. 3.0
1
NO
YES
2
NO
Replace the CPU board
Replace the driver board