R1224 Regulator
Installation Instruction
12-1001
24-30-01
Rev. M
: 01 Dec. 2021
Page: 6-5
© 2021 - Hartzell Engine Technologies - All rights reserved
WARNING:
TO PREVENT DAMAGE TO AIRCRAFT OR UNIT, READ AND UNDERSTAND ALL
INSTRUCTIONS PRIOR TO APPLYING POWER TO UNIT.
Current applications and specific regulator conversion/installation guides are available online at
www.planepower.aero or www.hartzell.aero
NOTE:
Use appropriately sized M7928/5 splices, M7981/1, ring lugs, and MIL-W-22759/16 wire.
6.2 Single Engine
A. Installation
(1) Remove existing regulator and solid-state over-voltage module (if installed).
(2) Install the regulator (R1224/R1224B/R1224J) in same location as regulator being replaced. If
mounting holes do not align, add mounting holes as required using acceptable methods, techniques
and practices such as those found in AC 43-13-1B and AC 43-13-2B.
(3) Connect GRND terminal to aircraft ground. It is critical that the regulator ground is connected to
airframe ground. Without this ground, the regulator and its internal overvoltage protection cannot
function.
(4) Connect the FLD terminal to the FIELD (brush) terminal of the alternator.
(5) Connect the ENABLE terminal to the regulator/field power source (the wire from the cockpit
ALTERNATOR FIELD switch which is fed from a 7.5 max amp breaker). Note: In order for the over
voltage protection circuit to operate the enable terminal must be connected to an operational circuit
breaker. (In the event of an over-voltage condition the over-voltage protection circuit will cause the
circuit breaker to trip removing all power from the regulating circuit.) Do not install the regulator in any
aircraft that has an automatic resetting circuit breaker in the enable line.
(6) If the regulator being replaced has a connection to the AUX terminal on the alternator, connect this wire
to the AUX terminal. If not, install a jumper wire between AUX and ENABLE. Note: No connection to AUX
terminal is necessary if an alternator out lamp is not installed.
NOTE:
For superceded versions of the regulator (Rev B & previous) indicated by silver label, step 7
does not apply and no sense terminal exists. Wiring of a ‘Sense’ terminal on these regulators
will result in damage to the regulator.
(7)
If an ALTERNATOR out lamp is installed in the aircraft and is to be actuated by the regulator, connect the
negative wire of the lamp to the LAMP terminal of the regulator.
(8) Remove the regulator cover and ensure that the internal jumper #1 and jumper #2 are set to the proper
voltage for the aircraft system. Refer to Figure 6-1
.
(9)
With the engine running and the alternator switch turned on, using a small screwdriver, set the regulator’s
voltage adjustment so that the bus voltage, as measured at the ENABLE terminal is the desired value.
Refer to aircraft maintenance manual or battery manufacturer’s data for proper voltage setting.
(10) Reinstall the regulator cover.
6.3
Multi-Engine
A. Installation
(1) For both regulators, perform steps 1 thru 10 of the Single Engine procedure, section 6.2.
(2) Choose one regulator as the Master. It can be either. Connect the OUT terminal of the Master Regulator
to the IN terminal of the other regulator.