Measurement Computing TempScan/1100 - Manual (Page 32)

1-18 System Overview 899493 TempScan / MultiScan User's Manual
To change the operating voltage of the TempScan/1100, MultiScan/1200, Exp/10A, and/or Exp/11A unit,
it is necessary to open the enclosure. However, before modifying the voltage, disconnect any input or
output connections from the rear panel of the affected unit and then disconnect the power cord from the
power line terminal.
Line voltage must be set for 105-125 or 210-250 VAC to match the power being supplied to the
TempScan/1100, MultiScan/1200, Exp/10A, and/or Exp/11A unit. If the line voltage is changed, the fuse
must also be changed. Refer to the following text for the line voltage switch and fuse locations.
Line Voltage Selection
As already mentioned, the TempScan/1100, MultiScan/1200, Exp/10A and Exp/11A unit can each operate
with 105-125 or 210-250 VAC, 50-60 Hz power, as set by its internal line-voltage switch (labelled S2 or
SW2). Each unit is shipped from the factory with this operating voltage setting marked on its rear panel.
If this is not the appropriate power setting to be supplied to the unit, then the line voltage and power fuse
must be changed to avoid damage to the unit. The locations of switch S2 or SW2 and the fuse are shown
in the figures. The line-voltage selection procedure is outlined in the following steps.
WARNING
Do not perform the procedures for line voltage selection and fuse replacement,
unless qualified to do so! These procedures are intended to be used by qualified
service personnel only!
WARNING
Never disassemble the unit casing while it is connected to the AC power line!
Internal voltage potentials exist which could cause bodily injury or death!
WARNING
Never disconnect the AC power line from the unit while its scanning cards are
connected to an external device! Common mode voltage potentials exceeding 60
VDC or 30 Vrms at the terminals, may exist which could cause bodily injury or
death!
Note: If disassembly or disconnections are necessary, first turn off the power, then disconnect the
scanning cards, next disconnect the AC power line, and then any other cables, prior to
disassembly.
To Change the Line-Voltage Selection
1. Turn off the power, disconnect the scanning cards, the power line cord, and then all other cables from
the unit.
2. Place the unit on a flat surface. For the TempScan/1100, MultiScan/1200, and/or Exp/10A: Remove
the six screws on top of the case and remove the top cover. For the Exp/11A: Loosen the two thumb
screws – one at each end – of the power module (left-most panel) and slide out the power module.
3. Located next to the main power supply transformer is the line voltage selection switch (labeled S2 or
SW2). Using a small screwdriver, insert the tip of the screwdriver into the slot of the switch and slide
the switch to the left or right until it "clicks" into place with the desired line voltage selection visible.