C.E. Niehoff & Co. A2-334, A2-335 Regulator Installation

A2-334 & A2-335

Regulators

Installation Instructions

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

Note: On Group 31 batteries, if boiling or excessive gassing occurs with high voltage
setpoint (position 3), change to medium voltage setpoint (position 2).

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:

• Mount A2-334 regulator on alternator in the
same position as the previous regulator. Use
screws and washers (if supplied). Torque
regulator mounting screws to 8.5 Nm/75 lb. in.

• Mount A2-335 regulator in remote location
specified by customer.

Maintenance (D Category)
Maintenance-Free (Group 31)
Maintenance-Free (Group 31)

Battery Type

Battery Isolator setpoint

3. Plug the alternator-to-regulator harness into the
regulator.

4. Regulator connections:

• Connect IGN terminal to ignition source
through existing switch. Torque M5 terminal
nut on regulator to 4.5 Nm/40 lb. in.

• If required, 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.

2

3

1

Figure 1 – 4 Voltage Setpoints

4

C. E. Niehoff & Co. • 2021 Lee Street • Evanston, IL 60202 Tech Services Hotline [phone]

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