Bradford White Copper Brute ll BWCH, Руководство пользователя

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Page 14
B
RADFORD
W
HITE
C
ORP.
Figure 5. Analog Input and Output Jumper Placement
3.C.2.b Cascade RS485
Prior to wiring Copper Brute ll units for cascade
operations, select one Copper Brute ll as the lead
boiler/heater. Other Copper Brute lls connected to the
lead boiler/heater will be referred to as lag units.
Communication between lead and lag units is
accomplished using RS485. When wiring Copper
Brute ll units for cascade operations, use terminals
22 (B), 23 (A), and 24 (GND) of the output terminal
strip. Use 2-wire twisted pair, shielded w/drain,
communication cable between units. Referring to
Figure 6, connect one end of the twisted pair wires
to A (terminal 23), and the other to terminal B
(terminal 22), and the drain wire to GND (terminal
24). Connect the other end of the cable to the next
Copper Brute ll, matching the termination wiring on
the previous unit, except for GND. Only connect the
drain wire to ground on one end of the cable to avoid
ground loop issues. If more than two Copper Brute
ll units are cascaded together, daisy chain the wiring
from Copper Brute ll to Copper Brute ll, keeping the
cables as short as possible.
A system supply sensor must be installed and
connected to the lead boiler, see System Supply in
Section 5.3.1.4 – Temperature Sensors. The lead
boiler will use this system supply sensor as the
temperature control sensor for cascade operations.
CH1/DHW1 terminals are used to initiate a heat
demand at the lead boiler, refer to CH1/DHW1 in Heat
Demands of the Installation Manual (Doc 1392).
3.C.2.c BAS RS485
These terminals, when used, are for RS485 serial
communication with a BAS system using BACnet
MS/TP or Modbus protocols. Use 2-wire twisted pair,
shielded w/drain, communication cable between the
BAS and Copper Brute ll.
3.C.2.d 24VAC
There are terminals for 24VAC on the output terminal
strip. These terminals are reserved for Copper Brute ll
low-temp units or a low water cuto-off option kit.
0 - 10VDC
NO JUMPER
0 - 10VDC
JUMPERS
ANALOG OUTPUTS
JUMPERS
4-20 mA
JUMPER
4 - 20mA
ANALOG
INPUTS