C.E. Niehoff & Co. A2-149/A2-155 Regulator Installation - Manual

II0118B Page 1 of 1
A2-149 & A2-155
Regulators
C. E. Niehoff & Co. • 2021 Lee Street • Evanston, IL 60202 Tech Services Hotline 800-643-4633
Table 1 – Voltage Select Switch Position
4 Voltage Setpoints (Fig. 1)
Position 1 14.0 V
Position 2 14.4 V
Position 3 14.8 V
Position 4 15.5 V
Battery Type
Maintenance (D Category)
Maintenance-Free (Group 31)
Maintenance-Free (Group 31)
Battery Isolator setpoint
Note: On Group 31 batteries, if boiling or excessive gassing occurs with high voltage
setpoint (position 3), change to medium voltage setpoint (position 2).
Figure 1 – 4 Voltage Setpoints
1. Before installing, turn regulator over and select
appropriate voltage setpoint for battery type
(See Table 1 and Fig. 1).
2. Install new regulator as described below:
a. Mount new regulator on alternator in the
same position as the previous regulator.
b. Use screws and washers (if supplied).
Torque regulator mounting screws to
8.5 Nm/75 lb. in.
3. Plug the alternator-to-regulator harness into the
regulator.
4. A2-155 regulator connections:
• Connect IGN terminal to ignition source
through existing switch. Torque M5 terminal
nut on regulator to 4.5 Nm/40 lb. in.
• Connect P terminal to tachometer or relay.
P terminal taps AC voltage, typically half
the charge voltage. Torque M6 terminal nut
on regulator to 4.5 Nm/40 lb. in.
Installation Instructions
1
2 3
4
5. A2-149 regulator connections:
• D+ terminal provides 14 VDC voltage output
to multiplex controller. When connecting D+
terminal to controller through a relay, the
relay coil must be diode protected and rated
for proper voltage. Torque M5 terminal
nut on regulator to 4.5 Nm/40 lb. in.
• Connect R terminal to tachometer or relay.
R terminal taps AC voltage, typically half the
charge voltage. Torque M6 terminal nut
on regulator to 4.5 Nm/40 lb. in.