Piper Arrow IV, Maintenance Manual

Page: 188 / 752

GENERAL.
This section contains instructions for correcting difficulties which may arise in the operation of the
electrical system in PA-28RT-201 and PA-28RT-201T airplanes.
The instructions are organized so the mechanic can refer to: Description and Principles of Operation for a
basic understanding of the various electrical systems; Troubleshooting for a methodical approach in locating
the difficulty; Corrective Maintenance for removal, repair and installation of components; and adjustments and
tests for operation of the repaired system.
DESCRIPTION AND OPERATION.
Electrical power is supplied by a 14-volt, direct current, negative ground electrical system. A 12-volt
battery is incorporated into the system to furnish power for starting and as a reserve power source in case of
alternator failure. The battery on the PA-28RT-201 is mounted on the firewall of the aircraft in between the
engine mount. Access to the battery on the PA-28RT-201T, is through the aft side of the baggage compartment.
The electrical generating system consists of an engine driven 60 AMP alternator for the PA-28RT-201 or a
65 AMP alternator for the PA-28RT-201T. A solid state voltage regulator maintains the systems bus voltage at
14-volts. Also incorporated is an overvoltage relay, which prevents damage to electrical and avionics
equipment in case of a regulator malfunction. The Overvoltage Relay and Voltage Regulator are located under
the instrument panel mounted to a plate which is connected to longerons on the left side of the aircraft at
station 50.0 and waterline 42.0. The loads from the electrical bus systems are protected by manual reset type
circuit breakers mounted on the lower right hand side of the instrument panel.
The master switch must be ON before any electrical equipment will operate. The master switch controls
the battery relay and field circuit. This switch is a double pole single throw type.
The lighting system for night time operation is optional equipment and consists of a landing light,
anticollision lights and navigation lights.
TROUBLESHOOTING.
Troubles peculiar to the electrical system are listed in Chart 2401 along with their probable causes and
suggested remedies. The wiring diagrams included at the end of this section will give physical breakdown of
the different electrical circuits used in these airplanes.
After the trouble has been corrected, check the entire system for security and operation of its components.
—WARNING—
All checks and adjustments of the alternator and/or its
components should be made with the engine stopped. Therefore,
to complete some checks or adjustments, it will be necessary to
remove these units from the airplane and place on a test stand.
24-02-00
Page 24-01
Revised: August 17, 1982
1H20
PIPER AIRCRAFT
PA-28RT-201 / 201T
MAINTENANCE MANUAL