C.E. Niehoff & Co. C505 Troubleshooting Guides - Manual (Page 2)

Page 2 TG70C
Section A: Description and Operation
CEN C505, C527, C531, and C534 Alternators/Regulators Description and Operation
C505, C527, C531, and C534 14 V (360 A) alternators are internally rectified. All windings and current-transmitting
components are non-moving, so there are no brushes or slip rings to wear out.
• When controlled by the
A2-334 (C505, C527 or C531 alternator-mounted) or A2-335 (C527 or C531 remote-mounted)
regulator, after engine is running, the alternator is externally energized when the battery master switch on the vehicle
is turned on and regulator receives energize signal through IGN terminal. Regulator monitors alternator rotation and
provides field current only when it detects alternator shaft rotating at or above idle speed. After regulator detects alter-
nator rotation, it gradually applies field current, preventing an abrupt mechanical load on accessory drive system.
The soft start may take up to 20 seconds.
• When controlled by the A2-343 (C527 alternator-mounted), A2-348 (C527, C531, or C534 alternator-mounted) or
A2-350 (C527, C531, or C534 remote-mounted) regulator, the alternator is externally energized when the battery mas-
ter switch on the vehicle is turned on and provides power to the regulators through the IGN circuit; can also operate
without vehicle connection to the IGN circuit, and instead provide power by sensing rotation through the regulator’s
AC circuit.
After field coil is energized. AC is rectified into DC output through diodes in rectifier housing and supplied to the battery
through the alternator B+ circuit. See schematic diagrams on pages 4 and 5. Alternator output current is self-limiting
and will not exceed rated capacity of alternator. Regulator maintains alternator output voltage at pre-determined regu-
lated setting (see Table 1 or 2 below for setpoints) as vehicle electrical loads are switched on and off.
A2-334 and A2-335 regulators furnished with some units include:
• External IGN terminal for energize connection.
• P terminal that can provide optional AC voltage tap. P terminal signal frequency (Hz) x 10 = alternator shaft rpm.
• Tricolored LED. See page 6.
• Regulator fixed (flat temperature compensation) setpoints shown in Table 1 are selected based on battery type. Battery
type selection and battery maintenance/function are the sole responsibilities of the customer.
Figure 2—Voltage Setpoints
Table 1 — A2-334 & A2-335 Regulator Setpoint Switch Position
Voltage Setpoint (±0.2 V)* Battery Type*
Position 1 14.0 V Maintenance (D Category)
Position 2 14.4 V Maintenance-free (Group 31)
Position 3 14.8 V Maintenance-free (Group 31)
Position 4 15.5 V Battery Isolator in Charging System
A2-343, A2-348, and A2-350 regulators furnished with some units includes:
• (A2-343 only) No external terminals, only a special 3-pin vehicle harness connector providing one pin for optional AC
voltage tap (PHASE OUT), one pin for DC voltage signal to vehicle electrical system confirming alternator operation
(D+), and one pin for the ignition connection (IGN). This regulator can function with or without vehicle ignition. When
necessary, IGN circuit in vehicle 3-pin harness is connected to vehicle ignition to provide battery voltage when engine
is running. Circuit should be off (no voltage present) when vehicle ignition is off or engine is not running.
• (A2-348 & A2-350 only) P terminal that can provide optional AC voltage tap. P terminal signal frequency (Hz) x 10 =
alternator shaft rpm.
• (All models) Overvoltage cutout (OVCO). See pages 6-7.
• (All models) Tricolored LED. See page 6.
• (All models) Battery type selection and battery maintenance/function are the sole responsibilities of the customer.
• (All models) Temperature-voltage sense/J1939 connector to be used with optional harness.
— When temperature-voltage sense/J1939 harness is not connected, regulator will operate in fixed voltage setting
determined by the select switch position on the bottom of the regulator. See Column 2 in Table 2.
— When temperature-voltage sense/J1939 harness is connected, regulator will automatically optimize the charge volt-
age for battery type based on temperature. Also, vehicle manufacturer-requested functions of J1939 interface are
available through connector. See Column 3 in Table 2.
Figure 3—Voltage Setpoints/
Battery Selection
Table 2 — A2-343, A2-348, & A2-350 Regulator Voltage/Battery Switch Position
Switch Position
T-VS/J1939 Harness Not
Connected (Voltage Select)
T-VS/J1939 Harness Connected
(Battery Select)
Position 1 13.8 V Maintenance (D Category)
Position 2 14.0 V Maintenance-free (Group 31)
Position 3 14.3 V AGM
Position 4 14.5 V DO NOT USE POSITION # 4
* Voltage setpoint can depend on temperature or climate condition, as well as battery type. If boiling or
excessive gassing occurs with higher voltage setpoint, change to next lower voltage setpoint.