Princeton 4411-0087 Manuale Utente

80 

ST-133 Controller Manual 

Version 3.B 

 

The appropriate voltage setting for your country is set at the factory and can be seen on 
the back of the power module.  If your voltage source changes, you will need to change 
the voltage setting and you may need to change the fuse configuration. 

Use proper fuse values and types for the controller and detector to be properly protected.  

Before opening the power module, turn the Controller OFF and unplug the 
powercord.

 

1.  As shown in Figure 39, place the flat 

side of a flat bladed screwdriver 
parallel to the back of the Controller 
and behind the small tab at the top of 
the power module, and twist the 
screwdriver slowly but firmly to pop 
the module open.  

2.  To change the voltage setting, roll the 

selector drum until the setting that is 
closest to the actual line voltage is 
facing outwards. 

3.  Confirm the fuse ratings by removing the 

two white fuse holders. To do so, simply 
insert the flat blade of the screwdriver 
behind the front tab of each fuse holder 
and gently pry the assembly out.  

120Vac

~

Selector Drum

Fuse Holders

 

 

4.  Refer to the Fuse/Voltage label (above or below the Power Module) to see which 

fuses are required by the selected voltage. If Controller power switch is on the back 
of the ST-133, the Fuse/Voltage label is located below the Power Module.  

5.  After inspecting and if necessary, changing the fuses to those required by the 

selected voltage, reinstall the holders with the arrow facing to the right.  

6.  Close the power module and verify that the correct voltage setting is displayed. 

7.  Verify that the Controller power switch is in the OFF position and then plug the 

powercord back into the power module.