Siemens SG020 - Manual (Page 12)

GENERATOR AC LEAD CONNECTIONS
See “Voltage Codes”. This generator may be rated
at any one of three voltages, either single-phase or
three-phase. The electrical wires in the unit’s AC con-
nection (lower) panel should be installed according to
the number of leads and the voltage/phase required
for the application. If there are any questions regard-
ing lead connection, refer to the wiring diagrams at
the back of this manual.
Voltage codes apply to the type of stator assembly
installed on a particular generator.
FOUR-LEAD, SINGLE-PHASE STATOR
Four-lead generators (see Figure 7.1) are designed to
supply electrical loads with voltage code “A” (240V,
1-phase, 60 Hz). Electrical power is produced in the
stator power windings. These windings were con-
nected at the factory to the main circuit breaker as
shown in Figure 7.1.
The rated voltage between each circuit breaker ter-
minal is 240V. The rated voltage between each circuit
breaker terminal and the neutral point 00 is 120V.
Figure 7.1 — Four-lead, Single-phase Stator
‹
ALTERNATOR POWER WINDING
CONNECTIONS
3-PHASE ALTERNATORS
The generator is designed to supply 3-phase electri-
cal loads. Electric power is produced in the alterna-
tor power windings. These windings were connected
at the factory to the main circuit breaker with a “Y”
configuration as shown in Figures 7.2 and 7.3.
The rated voltage between circuit breaker terminals
E1-E2, E1-E3 and E2-E3 is either 480V or 208V
depending on the model.
The rated voltage between each circuit breaker termi-
nal and the neutral point 00 is either 277V or 120V
depending on the model.
Figure 7.2 — Stator Power Winding
Connections - 3-phase, 277/480V (6 Lead)
S6
E3 S3
INTERNAL
CONNECTIONS
L-N
L-L
S4
E2 S2
S5
S1 E1
NEUTRAL
Figure 7.3 — Stator Power Winding
Connections - 3-phase, 120/208V (6 Lead)
E3 E2
00 (NEUTRAL)
E1
L-L
L-N
S1 S1
S4 S4
S6
S6
S3
S3
S5
S5
S2
S2
‹
7-1
Standby Generator Sets
General Information
ACConn001 Re v. 0 08/05