Syn-Tech Systems FuelMaster FMU-2500 Classic Installation Manual page 110

EIUs have an internal heater. With the heater on, an EIU consumes about 0.15 amp at 120 VAC. The
heater draws over 75% of the maximum power consumption, and will not be on during warm weather. An
EIU can control a maximum load of 5 amps. Motors cannot be controlled directly by the EIU.
EIUs have three major components (see Figure 4-32): a Cabinet, a Pedestal Cover and Wiring Assembly,
and a Pedestal. EIUs are constructed of lightweight, corrosion resistant aluminum.
There are no access panels in the EIU Pedestal. Wires in conduit must enter the Pedestal from the
bottom of the mount plate, and connect to the Pedestal Cover and Wiring Assembly at the top of the
Pedestal.
Inside dimensions of the EIU Pedestal are 3-1/2 inch x 3-1/2 inch. It may be necessary to bundle the three
conduit together to fit inside the Pedestal. See Figure 4-33 for EIU footprint dimensions.
Pulling Wires and Finishing Conduit
Verify that all required conduit are in place. Refer to Section III, Site Planning and Preparation, for
conduit requirements. There should be three conduit: one for incoming AC power from a circuit breaker,
one for communications from the Master FMU, and one to control the designated accessory. Pull the
following wires:
1. AC Power. Pull three 12 AWG THHN wires to the EIU from the circuit breaker panel; black for hot, white
for neutral, and green for ground. If the distance from the power source to the EIU exceeds 400 feet,
increase the size of the power wires to 10 AWG. Ensure approximately 3 feet of excess wire is extending
from the conduit to facilitate wire connections after EIU installation.
2. Master FMU/EIU Communications. Pull two twisted pair with drain 18 AWG shielded RS-422 cable from
the Master FMU to the EIU. If the cable length is under 150 feet, 22 AWG cable with the same
specifications may be used. At the EIU end, ensure approximately 3 feet of excess cable is extending from
the conduit to facilitate wire connections to the EIU. At the Master FMU sufficient cable will be necessary to
make connections to an I/O Silver Board mounted over the Pedestal I/O Board. Master FMU/EIU
communications cables cannot be "daisy-chained" between EIUs. Individual communications cables are
necessary from the Master FMU to each EIU.
3. Control of Accessory Controller. Pull two 14 AWG THHN wires from the EIU to the accessory controller.
The wiring diagram in Figure 4-34 calls out blue and orange, but any color may be used which are easily
identifiable when making the wire connections. Ensure approximately 3 feet of excess wire is extending
from the conduit to facilitate wire connections after EIU installation.
The seal-offs cannot be accessed after the EIU is mounted over the conduit.
As required, pour seal-offs on any conduit routed from/to a hazardous location.
Mounting the Pedestal.
A rigid base is necessary for mounting the EIU. Asphalt is not a satisfactory mounting surface. Perform
the following to mount the Pedestal:
1. Position the Pedestal centered over the conduit.
FuelMaster
®
Installation Manual
NOTE
108