AERCO BMK 3.0 LN Nat. Gas Jan 2011 - Manual (Page 19)

INSTALLATION
2-7
GND
NEU
L2
L3
L1
208 VAC, 3 PHASE
208 VAC, 3 Phase
GND
L2
L3
L1
460 VAC, 3 PHASE
460 VAC, 3 Phase
Figure 2-9
AC Terminal Block Configurations
2.9 MODES OF OPERATION AND FIELD
CONTROL WIRING
The Benchmark 3.0 Boiler is available in several
different modes of operation. While each unit is
factory c onfigured an d wired f or its intend ed
mode, s ome addit ional f ield wir ing m ay be
required to c omplete the installation. This wiring
is t ypically c onnected t o t he I nput/Output ( I/O)
Box located on the lower portion of the unit front
panel ( Figure 2- 10) beh ind the r emovable f ront
door.
To access the I/O Box terminal strips shown in
Figure 2-10, loosen t he f our c over s crews an d
remove the c over. A ll f ield wiring is ins talled
from the r ear of the pa nel b y r outing th e wires
through one of the four bushings provided.
TERMINAL
STRIPS
LOWER RIGHT CORNER
OF FRONT PANEL
Figure 2-10.
Input/Output (I/O) Box Location
Refer to the wiring d iagram pr ovided on t he
cover of the I/O Box (Figure 2-11) when making
all wiring connections.
Brief des criptions of eac h mode of oper ation,
and the ir wiring r equirements, ar e pr ovided in
the f ollowing par agraphs. Additional information
concerning field wiring is provided in paragraphs
2.9.1 thr ough 2.9. 9. Ref er to Chapt er 5 f or
detailed i nformation on t he av ailable m odes of
operation