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Chapter 2   Installation 
Power Supply Requirements 
The Ultra Twin can operate from AC supply or from a DC battery and is 
designed for use in temperatures between -4
o
F to +140
o
F (-20
o
C to +50
o
C). 
The AC is 115 +5% / -10% 50/60Hz. The DC is 18-30V. In all cases the 
Ultra Twin will typically consume 6W of power, with a maximum of 10W. 
If Ultra Twin has both an AC and DC supply available then the AC supply 
source  will  be  automatically  sensed  and  used,  should  the  AC  supply  be 
removed for any reason then the DC supply will take over. 
The  AC  and  DC  wiring  should  be  completed  using  either  16  –  14AWG 
(1.5–2.5mm
2
)  stranded  or  16  –  14AWG  (1.5–4mm
2
)  solid  wire,  with  all 
terminals being tightened to 4.5in. lbs. (0.5Nm). 
An external supply isolator/circuit breaker (AC or DC) must be fitted near to 
the unit and labelled to identify the instrument to which it refers. 
Safety Symbols 
Detailed  below  are  descriptions  and  meanings  of  safety/warning  symbols 
that are used on the Ultra Twin and in this manual.