Sierra INNOVA-FLO 220 - Manual (Page 33)

Series 220/221 Instruction Manual Chapter 2 Installation
Wiring Connections
Warning!
To avoid potential electric
shock, follow National Electric
Code safety practices or your
local code when wiring this
unit to a power source and to
peripheral devices. Failure to
do so could result in injury or
death. All wiring procedures
must be performed with the
power off.
The NEMA 4X enclosure contains an integral wiring compartment with one
dual strip terminal block (located in the smaller end of the enclosure). Two
3/4-inch female NPT conduit entries are available for separate power and
signal wiring. For all hazardous area installations, make sure to use an
agency-approved fitting at each conduit entry. If conduit seals are used, they
must be installed within 18 inches (457 mm) of the enclosure.
Input Power Connections
To access the wiring terminal blocks, locate and loosen the small set screw
which locks the small enclosure cover in place. Unscrew the cover to expose
the terminal block.
DC Power Wiring
Connect 4-20 mA loop power (12 to 36 VDC) to the +Pwr and –Pwr termi-
nals on the terminal block. Torque all connections to 4.43 to 5.31 in-lbs (0.5
to 0.6 Nm). The DC power wire size must be 20 to 10 AWG with the wire
stripped 1/2 inch (14 mm). The nominal voltage required to operate the 4-20
mA loop is 12 volts at the meter. The 4-20 mA loop is optically isolated from
the flow meter electronics.
Figure 2-14. DC Power Connections
IM-22 2-19