Steffes 7140 - Manual (Page 19)

POWER LINE CARRIER (PLC) PEAK CONTROL
The Steffes Power Line Carrier (PLC) control system has the ability to communicate with the Comfort Plus
Commercial Hydronic system through the existing electrical circuits in the structure. With the power line carrier
option, hard wired low voltage connections from the power company's peak signaling switch connect directly to
the transmitting device. The switch signals peak control times to the transmitter, the transmitter sends the signals
to the Comfort Plus Commercial Hydronic system, which receives this information and responds accordingly.
In addition to providing peak control signals, the transmitter also provides outdoor temperature information for
automatic charge control, room temperature set back, and anticipated peak utility control signals (if applicable).
The PLC control is optional and must be ordered separately. If utilizing a PLC system, refer to the owner's
manual for information on the installation and operation of the PLC control system.
TIME CLOCK MODULE PEAK CONTROL
The Steffes Time Clock Module is another option for providing a peak control signal to the Comfort Plus Com-
mercial Hydronic. It mounts inside the system’s low voltage electrical compartment and interfaces with the
relay board via an interface cable. Peak control times must be programmed into the system once the module is
installed to enable the time clock feature. Refer to the instructions provided with the Time Clock Module for
more information on the installation and operation of this device.
LINE VOLTAGE PEAK CONTROL
Line voltage control is also an option, but is not the preferred method of control as it is usually more complex and
expensive. If line voltage control is utilized, the controls circuit must be powered with an uninterrupted circuit.
An external switching device, such as a relay panel, is necessary to directly control the heating element charging
circuits. If relying on this method of control, the faceplate on the system MUST continuously display a brick
core operating mode of “C” (charge) regardless of whether it is an off-peak or on-peak period.
LOW VOLTAGE ELECTRICAL CONNECTIONS - OUTDOOR
TEMPERATURE SENSOR (OPTIONAL)
The outdoor sensor monitors outdoor temperature and provides this
information to the system. The system responds by automatically storing
heat in its brick core according to outdoor temperature and heating
requirements.
Installation Methods: Hard wired to system to the "OS" and "SC"
terminals (default) OR connected to Power
Line Carrier (PLC)
Location of: Must be placed in a location where it can accurately sense
outdoor temperature and is not affected by direct sunlight
or other abnormal temperature conditions.
Wiring: · Route low voltage wire from the outdoor sensor to the electrical compartment through one of the low
voltage wire knockouts.
· Connect to "OS" and "SC" as shown in Figure 12 or to the two outdoor terminals as shown in Figures
13-15.
· If sensor wiring is routed through an external wall, the opening through which the wire is routed
MUST be sealed. Failure to do so may affect the accuracy of the sensor.
· The outdoor sensor is supplied with a lead length of 40 ft. If a greater wire length is needed, it can be
extended to a total of 250 ft.
· No other loads can be controlled or supplied through this cable. It is for connection of the outdoor
sensor ONLY.
· This low voltage cable MUST not enter any line voltage enclosure.
· Unshielded Class II (thermostat) wire can be used as extension wire provided it is segregated from
any line voltage cabling.
Installation
Comfort Plus Commercial Hydronic Installation
n
3.08
w If connecting to a Steffes PLC
system, follow the installation
instructions in the PLC system's
Owner's and Installer's Guide.
w Outdoor sensor wire MUST
NEVER be combined with other
control wiring in a multi-
conductor cable.
IMPORTANT