Heat Transfer MODCON VWH 300 HL, Installation & Maintenance

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UNUSED COMMUNICATION
BUS JACK AVAILABLE TO
CONNECT TO VISION 2.
UNUSED COMMUNICATION
B JACK AVAILABLE TO
CONNECT TO VISION 2.
Fig. 8-2
LP-205-JJ
PART 8: FIELD WIRING
(CONTINUED)
L. WIRING OF CASCADE SYSTEM
COMMUNICATION BUS
1. Use standard CAT3 or CAT5 computer
network patch cables to connect the
communication bus between each of the
boilers. Use standard ‘straight through’
cables for these connections.
Do not use
crossover cables. These cables are readily
available at any office supply, computer,
electronic, department or discount home
supply store in varying lengths. If you
possess the skills you can also construct
custom length cables.
2. It is recommended to use the shortest length
cable that will reach between the boilers and
create a neat installation. Do not run
unprotected cables across the floor or where
they will become wet or damaged. Avoid
running communication cables parallel and
close to or against high voltage (120 volt or
greater) wiring. HTP recommends that the
maximum length of communication bus
cables not exceed 200 feet.
3. Route the communication cables through
one of the knockouts in the cabinet.
4. Connect the boilers in a daisy chain
configuration as shown below. It is best to
wire the boilers using the shortest wire runs
rather than trying to wire them in the order
that they are addressed. The communication
bus jacks on the customer connection panel
are interchangeable so you can use either
one or both in any order to connect the cable
to. If you have connected the boilers to each
other properly, two of the boilers will have
one open connection port on them.
GAS-FIRED HOT WATER SUPPLY BOILER
Boiler Manual
48