Warning, Important, Air conditioner/heat pump interface – Steffes 6140 User Manual
Page 17: Line voltage electrical connections

Comfort Plus Commercial
Installation
n
3.08
Installation
AIR CONDITIONER/HEAT PUMP INTERFACE
When interfacing the Comfort Plus system with a heat pump, the
indoor coil MUST be placed on the return side of the Comfort Plus
system in a position that will provide even air flow through the coil. If
using a factory supplied return air plenum, the plenum is configured to
be the housing for the indoor coil. Remove the screws to the plenums
access cover and slide the coil into place inside the plenum. If not using
a Steffes supplied return air plenum, the installer will need to make
provisions in the plenum to accommodate the coil and air filter.
When interfacing a Comfort Plus system with an air conditioner, the
indoor coil can be placed on either the supply air or the return air side
of the system.
The condensate drain trap, in a heat pump or air conditioner installation,
should be designed for the vacuum in which the system is operating.
Typically, taller traps are better suited for these types of applications.
Refer to the Room Thermostat Connections Diagrams (Figures 14, 15 and 16) for more information on interfacing
the Comfort Plus with a heat pump or air conditioner.
WARNING
Risk of fire. Any one ducting system
MUST NOT contain more than one
air handling (blower) system. If the
application requires multiple Com-
fort Plus systems or it is necessary to
have multiple air handlers share the
same ductwork, you MUST contact
Steffes Corporation. There are
special installation requirements
that MUST be performed in an
application such as this.
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 (ele-
ment) circuits. 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 12B.
To determine the correct wire size required for each circuit feeding the system, refer to the Specifications (Page
A.01) and the system's identification label located on the lower left side of the system. (Reference Sample Label
Figure 11.)
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 breakers. Refer to the Line Voltage
Wiring Diagrams (Pages A.03 - A.04) 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 alternated
as shown in Figure 12A.
IMPORTANT