Error 15 - Dc Bus Over Voltage - Precor TRM 885.v2 Service Manual

3. If the fan is not turning at all, power down the treadmill then open the case of the control
module – verify the fan is plugged in.
4. Rotate the fan with hand, it should turn smoothly with no binding or scraping, all fan blades
intact.
5. If the fan does not spin or turn smoothly, replace the control module.
Error 15 – DC Bus Over Voltage
MCL – Green
ASL – Yellow Solid
Description
The DC bus (motor) voltage is monitored. When the treadmill is used by a vigorous exerciser
walking or running at steep incline or when pushing against the handlebars while the belt is
moving, the AC motor becomes a generator forcing power back into the Motor Controller. This
excess power would cause the bus voltage to increase enough to damage the control module
were it not for the DB (dynamic brake) resistor, which automatically switches on to absorb the
excess power. Error 15 is an indication that the Bus Voltage exceeded the bus voltage limits,
either because the DB system wasn't functional or because the bus voltage power exceeded the
DB system limit..
Possible Remedies
1. Check the error log to determine the error frequency and repeatability.
a. If one time event, clear the error log and return to service.
b. If repeated occurrences of the error are shown, clear the error log, raise the elevation to
15%, and walk at a fast but comfortable pace, pushing slightly against the handrail. If
you are able to easily generate an Error 15, replace the DB resistor.
2. Check DB resistor connection
a. Turn off unit.
b. Verify all DB resistor connections are connected and are seated properly.
3. Check DB resistance
a. Check the DB resistance. It should be 90 to 110 ohms. If greater than 150ohms, replace
the DB resistor.
b. Check the resistance between either terminals of the switch connector (smaller black) to
either terminal of the resistor element connector (larger white/natural). The resistance
should be greater than 1Meg of resistance. If less than 1Meg, replace the DB resistor.
4. If none of the above, replace the motor controller.
5. If NO, and the problem has only happened once or twice for this treadmill, dismiss it and
clear the error logs.
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