Steffes 7140 - Manual (Page 17)

Installation
Comfort Plus Commercial Hydronic Installation
n
3.06
SAMPLE SYSTEM IDENTIFICATION LABEL
FIGURE 8
208/240 SINGLE PHASE
CIRCUIT PHASING CONNECTIONS
FIGURE 9A
LINE VOLTAGE ELECTRICAL CONNECTIONS
In standard configuration, the system is wired for connection to
240V; however, the element circuits can also be connected to
208V. A 208V connection derates the charging input of the
system by 25%. If a system rated specifically for 208V is
required, contact the factory. The controls circuit in the system
MUST be connected to 240V/208V.
277/480V and 347/600V Comfort Plus Commercial
systems are configured to use single feed only.
208/240V System Connections Only: The 60 amp breakers located
in the electrical compartment feed the core charging (element) cir-
cuits. The 15 amp breaker feeds the controls and blowers circuit. All
240V/208V systems are factory configured to be field connected to
multiple line voltage circuits. If a single feed line voltage circuit is
desired, an optional single feed kit is available from the factory.
277/480V and 347/600V System Connections Only: The fuse
block connection points and neutral connection block, located in the
line voltage side of the electrical compartment, feed the core charging
(heating element) circuits. This also provides power and the terminal
block connections for the primary side of the optional control voltage step-down transformer. Adjacent to these
terminals are the connection points for the transformer secondary. See Figure 9B.
To determine the correct wire size required for each circuit feeding the system, refer to the Specifications (Page
A.01-A.02) and the system's identification label located on the lower left side of the system. (Reference Sample
Label Figure 8.)
Step 1 Route all line voltage wires through a knockout and into the electrical panel.
Step 2 Make proper field wiring connections to the Comfort Plus Commercial system. Refer to the Line Volt-
age Wiring Diagrams (Pages A.04 - A.09) for more information on these connections.
HAZARDOUS VOLTAGE: Risk of electric
shock. Can cause injury or death. Do not
energize the system until installation is
complete. Equipment MUST be installed
by a qualified technician in compliance
with all applicable local, state, and
national codes and regulations.
WARNING
w To ensure proper operation and
safety, all line voltage circuits
must be segregated from low
voltage wiring in the system.
w To reduce electro magnetic fields
associated with electrical circuits
and to avoid induced voltage on
sensors and electronic devices,
the circuit phases MUST be alter-
nated as shown in Figure 9A.
IMPORTANT
The 60 AMP breakers are for internal
component protection only. Sizing of the
field wire and breaker size MUST be in
compliance with all applicable local,
state, and national codes and regulations.
Circuit Breakers
LIN
E
1
BLOWERS/CONTROLS CIRCUIT
LIN
E
2
LIN
E
1
LIN
E
2
LIN
E
1
LIN
E
2
LIN
E
1
LIN
E
1
LIN
E
2
To Serv
ice
(Break
er) Panel
CHARGE CIRCUIT #4
CHARGE CIRCUIT #3
LIN
E
2
CHARGE CIRCUIT #1
CHARGE CIRCUIT #2
277/480V AND
347/600V THREE
PHASE
FIGURE 9B