Technogym JOG EXCITE, Service Maintenance Manual

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JOG EXCITE: Service & Maintenance Manual - rev. 1.1
Page 3.6
3.2. TREAD BELT MOTOR DRIVE
3.2.1. M
ECHANICS
The tread belt is actuated by the motor through a linkage consisting of the motor pulley, the driving
roller and the belt which connects them. In this way, a given belt motor speed corresponds to a
predetermined linear tread belt speed.
3.2.2. C
ONTROLS
The control block diagram is as follows:
To actuate the motor, the display board communicates with the AT driver via the RS-485 serial
link. Based on the commands received, the AT driver drives the motor by applying a variable
frequency sinusoidal voltage: the frequency determines the speed of rotation of the motor and hence
the linear tread belt speed. The control may happen in “
Open loop
”, where the AT driver provides
to the motor a sinusoidal voltage at a frequency that theoretically set the motor running at the
selected speed.
During its movement, the AT driver continually checks the motor by monitoring its current draw. If
any problems are detected (low voltage, overcurrent, SW or HW problems with the AT driver itself,
etc....) it halts the motor and sends an alarm signal to the display board, which displays a “THE
EQUIPMENT IS BLOCKED” error message which can be associated with different inverter error
codes.
In addition, to protect the motor from overheating, each motor phase has a thermal cut-out
connected in series. If the temperature exceeds the threshold value, the thermal cut-outs open and
interrupt the circuit. The AT driver detects this condition as the opening of a NC external contact.
Display Board
AT driver
RS-485
CN2
J4
1-2-3/J5
M
Cut-out
4-5/J5
VAC
with variable frequency