Determine The Number Of Wires Needed - Bennett 3700 Series Installation Manual

Determine the Number of Wires Needed

The 531 commercial electronics package in the model 3700 unit is a very simple design. There will be
one "control" (CPU) board per hose. The dispenser may be ordered as a one or two hose unit. One
hose units have one control board, and two hose units have two control boards. The control board is
where the field wires will connect if the optional junction box is not ordered. The Installer will run power
wires to side 1 product "A" CPU/Control board. Side 1 will be the side with the serial tag located inside
the electronics enclosure on the deck to the right. If the dispenser is a dual product, Product A CPU
will be on side 1 to the right. If there are more than 1 CPU/Control Boards, the boards are factory wired
from board to board for power. Please refer to the Remote Power Wiring Diagram located in the Wiring
Diagram section of this manual:
Determine the wires needed in each step and add the number of wires from each step together to
determine total number of wires required.
Step 1. Dispenser Power - Every model of 3700 requires these wires:
(1) 12ga. Green ground wire
(1) 14ga Black L1 power wire for electronics power.
(1) 14ga. White for 115V neutral or red for 230V L2, for electronics power.
Step 2. Console Communications -If the dispenser is to be connected to a control console, remote
communication wires will be needed. The 3700 model dispenser uses RS485 communication to the
control console.
To side 1 Product "A" (CPU Board): (1) 18ga. wire for RS485 communication positive. (Orange)
Note - Use twisted wires for the communication wiring at 3 twists per foot. If there is more than one
CPU/Control Board, the RS485 data wires are wired at the factory from board to board. The Installer
does not have to pull 3 separate RS485 wires for each control board in the same dispenser. Please refer
to the RS485 Communication Wiring Diagram located in the Wiring Section of this manual.
Note - Belden twisted shielded cable is accepted as long as the drain is only terminated on one end.
Terminate the drain to the ground lug in the interface box within the building.
Step 3. Remote Dispensers (Submerged Pump) -a remote relay control wire will be required for
each plumbed product. If there is only one product, only one submerged pump control wire is needed. If
there is a second product, a second submerged pump control wire will be needed. Please refer to the
Remote Power Wiring Diagram located in the wiring section of this manual.
For Product "A" Hose Position (Control Board): (1) Blue 14ga. wire.
For Product "B" Hose Position (Control Board): (1) Brown 14ga. wire.
Step 4. Self-Contained (Suction Pump)- a separate circuit and circuit breaker will be required for
each pumping unit motor. Place the pumping unit motor power circuit breakers on the opposite phase
from the dispenser's electronic power or on 230VAC. This will keep the dispenser's electronic power
free from electronic noise. The dispenser may have one motor (single product) or two motors (dual
product). Each motor requires two field wires. Please refer to the Self Contained Power Wiring Diagram
located in the wiring section of this manual.
Needed for each Pumping Unit Motor :
(1) Red for L2 14 ga.* Hot & (1) White 14 ga. Neutral on 115V circuits
(1) Red for L2 14 ga.* Hot & (1) Black 14 ga. for L1 Hot for 230V circuits.
* Note: "L2" refers to a different phase leg from dispenser power. Runs longer than 50ft. will require
larger wires. Size wires to minimize voltage loss or run the motors on 230V circuits to minimize the
current in the wires.
115 or 230 Volt Installations
(1) 18ga. wire for RS485 communication negative. (Brown)
(1) 18ga. wire for RS485 communication common. (Black)
OR
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120001 Rev K 1-19-18