Procedure 5.2 - Troubleshooting The External A.c. Power Source - Precor 905e Service Manual

Procedure 5.2 - Troubleshooting the External A.C. Power
It is extremely important that any Precor treadmill be connected to and operated on a dedicated
20 amp A.C. circuit. A 20 amp dedicated circuit is defined as: a circuit fed by a 20 amp circuit
breaker that feeds a single load. A treadmill operating from a non-dedicated circuit or a circuit
breaker of less than 20 amps capacity will not have the necessary power available to operate
normally under higher load conditions. The lack of available power can cause any number of
symptoms ranging from numerous intermittent (seemingly inexplicable) error conditions, poor
speed control, or tripping the house circuit breaker.
If any of the above symptoms exist the external A.C. circuit must be checked and confirmed to be
a 20 amp dedicated circuit before troubleshooting the treadmill.
In addition the A.C. voltage must be checked. Nominal A.C. operating voltage on 120 Vac circuits
is 105 Vac to 120 Vac. Nominal A.C. operating voltage on 240 Vac circuits is 208 Vac to 240
Vac.
For operator safety considerations and to minimize electrostatic discharge conditions the A.C.
frame ground continuity must also be verified to be a low resistance connection to the A.C.
distribution ground bar.
Important
If the A.C. circuit feeding a treadmill is found to be a non-dedicated circuit or a circuit equipped
with a circuit breaker with a capacity of less than 20 amps, the A.C. circuit must be corrected to
be a 20 amp dedicated circuit before any reliable troubleshooting can be performed on the
treadmill. More importantly, a non-dedicated circuit may constitute a safety hazard to the
treadmill operator.
120 Vac Systems
120 Vac distribution systems utilize a single pole circuit breaker (hot lead) and a neutral lead
connected to a common neutral (ground) bar. The A.C. safety ground (green wire) is connected
to a separate ground bar in the distribution system.
The most common problems found are (1) the circuit is fed by a circuit breaker of less than 20
amp capacity, (2) the circuit breaker correctly feeds a single A.C. outlet but the neutral is
common between several A.C. outlets and (3) both the hot and neutral leads feed several A.C.
outlets. The appropriate correction action or actions (see below) must be followed if any of the
above conditions exist. Corrective actions should only be undertaken by a licensed
electrician.
1. The circuit breaker feeding the treadmill is not a 20 amp circuit breaker.
If the circuit breaker is greater than 20 amps, the circuit breaker should be replaced with a
20 amp circuit breaker. If the circuit breaker is less than 20 amps the circuit breaker must be
replaced with a 20 amp circuit breaker and the wiring from the A.C. distribution must be
capable of safely handing 20 amps. If the A.C. wiring is under sized, it must be replaced
with wire capable of safely handling 20 amps. Please, refer to local electrical codes when
determining the appropriate wire size for a 20 amp circuit.
Source
905E, 9.1, 9.10 Treadmills
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