Operator's Manual
First Edition • First Printing
26
T70 • T90 • T120
Part No. 134207
Voltage Selector Switch Operation
The voltage selector switch can affect the single-
phase receptacles provided on the unit. The
indicated voltages should be checked after
selecting the setting of the switch. The Y voltage
configuration of 480 and 240 will produce a voltage
of 139 on the GFI receptacles.
This generator set produces voltages that can
cause severe shock or death. Only qualified
electricians should perform electrical work.
Exercise extreme caution around any electrical
component when operating this unit.
Never operate the voltage selector switch while
the generator is running. This will result in
immediate damage to the switch, the generator or
the connected equipment and may result in serious
injury to the operator.
Note: Always make sure that the voltage selector
switch has been set to the desired range before
starting the generator set.
The voltage selector switch for all the generators
has three positions marked 480 / 277 - 3 phase,
240 / 139 - 3 phase, and 240 / 120 - 1 phase. Each
position gives a different output to the three-phase
distribution lugs (designated as L1, L2, L3 and N)
located on the distribution panel.
4
8
0 / 277, 3 - phase position
Output
(Hi Wye configuration)
Line - to - Line
4
8
0 VAC / 3P
(L1 to L2, / L2 to L3 / L1 to L3)
Line - to - Neutral
277 VAC / 1P
(L1, L2 or L3 to N)
240 / 139, 3 - phase position
(Lo Wye configuration)
Output
Line - to - Line
240 VAC / 3P
(L1 to L2, / L2 to L3 / L1 to L3)
Line - to - Neutral
139 VAC / 1P
(L1, L2 or L3 to N)
240 single phase
(Zig Zag configuration - L2 not used)
Output
Line - to - Line (L1 to L3)
240 VAC / 1P
Line - to - Neutral (L1 or L3 to N)
120 VAC 1P
Note: The Hi Wye and the Low Wye configurations
can be adjusted by using the voltage adjustment.
Once the required voltages are known, the
combination of the proper switch position and
voltage adjustment potentiometer allows for fine
tuning the voltage to the exact needs of the
application.
When the proper voltage selector switch position is
selected, lock the switch in that position. This
prevents the switch from being moved while the
unit is operating or by unauthorized personnel.
Damage to the unit and any connected equipment
will be avoided.
Operating Instructions
