Usage:
A compensating current transformer is used in self regulated constant voltage generators with serial numbers 600 and up. These generators can come connected for any of the voltages that follow:
NOTE: Both voltages of a (120/208, 120/240, 200/400 or 240/480) single voltage generator can be used at the same time. On the (120-240, 200-400 or 240-480) 10 wire dual voltage generators the leads can be connected to get one or the other of the voltages, not both at the same time. Rated voltage on dual voltage generators is for a line to line connection. A line to neutral connection will give 58% of the rated voltage.
| NOTICE |
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If the generator is operated at a voltage that is different than nameplate rating; you must operate with a different kW output limit. Use the formula that follows to find the kW limit for voltages other than nameplate. |
I and P.F. are constant, at nameplate rating. If output voltage is changed, the three phase kW limit will change.
Example:
The ampere rating on the generator must not be exceeded.
Three Phase Generators
120/208 Volt Generators
Saturable reactor (C) has the common tap connected to phase winding lead (t2) through regulator terminal (10). The 120V tap is connected to contact (D0), on voltage droop control switch (B), through regulator terminal (1). The generator neutral (T0) is connected to the regulator through regulator terminal (2).
120/208V generators can be made to give 127/220V or 139/140V service. If the wire on the 120V tap is moved to the 127V tap, the generator will give 220V line to line and 127V line to neutral.
| NOTICE |
|---|
The KW, KVA and ampere output of the generator must be limited to less than nameplate rating to help prevent damage to the generator field windings. |
To calculate the reduction necessary, use the formula that follows:
If the wire on the 120V tap is moved to the 139V tap, the generator will give 240V line to line and 138V line to neutral. The output of the generator must be limited to:
NOTE: When a 120/208V self regulated constant voltage generator is to be operated in parallel with a 120/208V "N" or "K" series self regulated saturated field generator, the saturable reactor must be connected to use the common and 127V taps.
NOTE: Make a mark (show new location) on the nameplate of the generator when reactor taps are changed from the original location.
A. Voltage droop transformer.
B. Voltage droop control switch.
C. Saturable reactor.
D. Full wave rectifier.
E. Generator armature (stator).
F. Generator field (rotor).
G. Exciter armature.
H. Voltage level resistor (if so equipped).
I. Blocking rectifier.
J. Voltage level rheostat.
K. Exciter field.
L. Exciter control field.
1, 2, 3, 4, 5, 6 and 10. Regulator terminals.
120/208 VOLT GENERATOR CONNECTION
A1 and A2. Exciter armature leads.
C1 and C2. Generator field leads.
F1 and F2. Exciter field leads.
S1 and S2. Exciter control field leads.
T0, T1, T2 and T3. Generator leads (outside generator).
t1, t3 and t8. Phase winding leads (inside generator).
120-240 Volt Generators
A. Voltage droop transformer.
B. Voltage droop switch.
C. Saturable reactor.
D. Full wave rectifier.
E. Generator armature (stator).
F. Generator field (rotor).
G. Exciter armature.
H. Voltage level resistor (if so equipped).
I. Blocking rectifier.
J. Voltage level rheostat.
K. Exciter field.
L. Exciter control field.
M. Voltage change terminal block.
1, 2, 3, 4, 5, 6 and 10. Regulator terminals.
120 VOLT GENERATOR CONNECTION
A1 and A2. Exciter armature leads.
C1 and C2. Generator field leads.
F1 and F2. Exciter field leads.
S1 and S2. Exciter control field leads.
T0, T1, T2 and T3. Generator leads (outside generator).
t1 through t9. Phase winding leads (inside generator).
The phase windings are connected in parallel for 120V operation or in series for 240V operation.
For 120V operation saturable reactor (C) has the common tap connected, through regulator terminal (10) and terminal 9 on the "L" side of voltage change terminal block (M), to generator lead (t8). The 120V tap is connected to the contact of voltage droop switch (B) that moves, through terminal 7 on the "L" side of voltage change terminal block (M) and terminal (1) of the regulator. Generator lead (t9) is connected to the regulator through terminal 8 on the "L" side of voltage change terminal block (M) and regulator terminal 2.
A. Voltage droop transformer.
B. Voltage droop switch.
C. Saturable reactor.
D. Full wave rectifier.
E. Generator armature (stator).
M. Voltage change terminal block.
1, 2 and 10. Regulator terminals.
240 VOLT GENERATOR CONNECTION
T0, T1, T2 and T3. Generator leads (outside generator).
t1 through t9. Phase winding leads (inside generator).
For 240V operation saturable reactor "C" has the common tap connected, through regulator terminal (10) and terminal 9 on the "H" side of voltage change terminal block (M) to phase winding lead (t2). The 139V tap is connected to the contact of voltage droop switch (B) that moves, through terminal 7 on the "H" side of voltage change terminal block (M) and terminal (1) of the regulator. Generator lead (T0) is connected to the regulator through terminal 8 on the "H" side of voltage change terminal block (M) and regulator terminal 2.
If the generator is connected for 240V but 220V operation is desired, move the wire from the 139V tap on the saturable reactor to the 127V tap. The generator can give nameplate rated amperes but because of the voltage reduction the available kW and KVA capacities will be 92% of the nameplate rating.
If the generator is connected for 240V but 208V operation is desired, move the wire from the 139V tap on the saturable reactor to the 120V tap. The generator can give nameplate rated amperes but because of the voltage reduction the available kW and KVA capacities will be 87% of the nameplate rating.
NOTE: Make a mark (show new location) on the nameplate of the generator when saturable reactor taps are changed from the original position.
240-480 Volt Generators
The phase windings are connected in parallel for 200 and 240V operation or in series for 400 and 480V operation.
Saturable reactor (C) has the common tap connected through regulator terminal (10) to phase winding lead (t8). The 139V tap is connected to the contact of voltage droop switch (B) that moves, through terminal (1) of the regulator. Generator lead (T0) is connected to the regulator terminal (2).
NOTE: The saturable reactor tap is the same for:
- 240-480 Volts 60 HZ240-480 Volts 50 HZ200-400 Volts 50 HZ
240-480V and 200-400V at 50 HZ is made possible by adjustment of the voltage level rheostat.
A 240-480V generator can be made to give 220-440V or 208-416V service. If the wire on the 139V tap of the saturable reactor is moved to the 127V tap, the generator will operate as a 220-440V unit. The generator can give nameplate rated amperes but because of the voltage reduction the available kW and KVA will be 92% of the nameplate rating.
If the wire on the 139V tap is moved to the 120V tap, the generator will operate as a 208-416V unit. The generator can give nameplate rated amperes but because of the voltage reduction the available kW and KVA will be 87% of the nameplate rating.
NOTE: Make a mark (show new location) on the nameplate of the generator when saturable reactor taps are changed from the original position.
A. Voltage droop transformer.
B. Voltage droop switch.
C. Saturable reactor.
D. Full wave rectifier.
E. Generator armature (stator).
1, 2 and 10. Regulator terminals.
240 VOLT GENERATOR CONNECTION
T0, T1, T2 and T3. Generator leads (outside generator).
t1 through t9. Phase winding leads (inside generator).
A. Voltage droop transformer.
B. Voltage droop switch.
C. Saturable reactor.
D. Full wave rectifier.
E. Generator armature (stator).
1, 2 and 10. Regulator terminals.
480 VOLT GENERATOR CONNECTION
T0, T1, T2 and T3. Generator leads (outside generator).
t1 leads (inside generator).
600 and 2400 Volt Generators
Saturable reactor (C) has the common tap connected to the phase windings of (T2) through regulator terminal (10). The 120V tap (127V tap on D375 2400V generator) of the saturable reactor is connected to the contact of voltage droop switch (B) that moves, through regulator terminal (1). The common tap is connected to the phase windings of (T2) through regulator terminal (10). The generator neutral (T0) is connected to the regulator through regulator terminal (2).
NOTE: For more information on the exact location of the phase winding tap for the regulator reference lead make reference to REWIND INFORMATION.
This arrangement gives no more than 139V at the saturable reactor. This is the highest voltage in the regulator compartment.
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A 2400V generator must not be operated, even on an open circuit, without a good ground connection made to (T0). |
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A. Voltage droop transformer.
B. Voltage droop switch.
C. Saturable reactor.
D. Full wave rectifier.
E. Generator armature (stator).
1, 2 and 10. Regulator terminals.
600 AND 2400 VOLT GENERATOR CONNECTION
T0, T1, T2 and T3. Generator leads (outside generator).
t1, t2, t3 and t5. Phase winding leads (inside generator).
Single Phase Generators
A three phase generator can be connected to give 2 or 3 wire single phase operation. When a three phase generator is connected for single phase operation it will give 57% of its kW and KVA rating.
120-240 Volt Generators
The 2 wire low voltage connection will give 120V L1 to L2. The generator phase windings are connected in parallel. The saturable reactor has the common tap connected through regulator terminal (10) and terminal 9 of voltage change terminal block (M) to phase winding lead (t8). The 120V tap is connected through terminal 7 of the voltage change terminal block and regulator terminal (1) to the contact of the voltage droop switch that moves. Phase winding lead (t9) is connected to the regulator through terminal 8 of the voltage change terminal block and regulator terminal (2). Phase winding leads (t1, t4, t7 and T0) are not used for single phase service and must be carefully insulated.
A. Voltage droop transformer.
B. Voltage droop switch.
C. Saturable reactor.
D. Full wave rectifier.
E. Generator armature (stator).
M. Voltage change terminal block.
1, 2 and 10. Regulator terminals.
2 WIRE LOW VOLTAGE
T 0, L1 and L2. Generator leads (outside generator).
t 1 through t9. Phase winding leads (inside generator).
2 WIRE HIGH VOLTAGE CONNECTION
A. Voltage droop transformer. E. Generator armature (stator). T0, T1, T2, T3, L1 and L2. Generator leads (outside generator). t1 through t9. Phase winding leads (inside generator). 8 and 9. Terminals on voltage change terminal block.
The 2 wire high voltage connection will give 240V L1 to L2. The generator phase windings are connected in series. Connections to the saturable reactor, regulator, voltage change terminal block and generator are the same as for 120V, 2 wire, single phase. Leads (t1, t4, t7 and T0) are not used and must be carefully insulated.
3 WIRE HIGH-LOW VOLTAGE CONNECTION
A. Voltage droop transformer. E. Generator armature (stator). T0, T1, T2, T3, N, L1 and L2. Generator leads (outside generator). t1 through t9. Phase winding leads (inside generator). 8 and 9. Terminals on voltage change terminal block.
The 3 wire high-low voltage connection will give 120V, L1 to N and L2 to N or 240V L1 to L2. The generator phase windings are connected in series. Connections to the saturable reactor, regulator, voltage change terminal block and generator are the same as for 120V, 2 wire, single phase. Leads (t1, t4, t7 and T0) are not used and must be carefully insulated.
NOTE: 120/240 single phase generators can be adjusted to give 110/220V or 115/230V.
Connections for 50 cycle, 1 phase, 120/240 generators are the same as those shown for 120/240V, 60 cycle, 1 phase generators.
240-480 Volt Generators
2 WIRE LOW VOLTAGE CONNECTION
A. Voltage droop transformer. E. Generator armature (stator). T0, T1, T2, T3, L1 and L2. Generator leads (outside generator). t1 through t9. Phase winding leads (inside generator). 2 and 10. Regulator terminals.
The 2 wire low voltage connection will give 240V L1 to L2. The generator phase windings are connected in parallel. The regulator and saturable reactor connections are the same as for 240-480V three phase operation. Phase winding leads (t1, t4 and t7 are not used for single phase service and must be carefully insulated.
The 2 wire high voltage connection will give 480V L1 to L2. The generator phase windings are connected in series. The regulator and saturable reactor connections are the same as for 240-480V three phase operation. Phase winding leads (t1, t4 and t7) are not used for single phase service and must be carefully insulated.
The 3 wire high-low voltage connection will give 240V L1 to N and L2 to N or 480V L1 to L2. The generator phase windings are connected in series. Phase winding leads (t1, t4 and t7) are not used and must be carfully insulated.
Connections for 50 cycle, 1 phase, 200-400V and 240-480V generators are the same as those shown for 240-480V, 60 cycle, 1 phase generators.
2 WIRE HIGH VOLTAGE CONNECTION.
A. Voltage droop transformer. E. Generator armature (stator). T0, T1, T2, T3, L1 and L2. Generator leads (outside generator). t1 through t9. Phase winding leads (inside generator). 2 and 10. Regulator terminals.
3 WIRE HIGH-LOW VOLTAGE CONNECTION
A. Voltage droop transformer. E. Generator armature (stator). T0, T1, T2, T3, L1, L2 and N. Generator leads (outside generator). t1 through t9. Phase winding leads (inside generator). 2 and 10. Regulator terminals.