EC7830, RM7830A,EC7850A,RM7850A 7800 SERIES RELAY MODULES
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66-1092—2
Table 1. Recommended Wire Sizes and Part Numbers.
The KDM, Data ControlBus Module™ (for remote mounting or communications) or Communication Interface ControlBus™
Module must be wired in daisy chain configuration, 1(a)-1(a), 2(b)-2(b), 3(c)-3(c). The order of interconnection of all the devices
listed above is not important. Be aware that modules on the closest and farthest end of the daisy chain configuration string
require a 120 ohm (1/4 watt minimum) resistor termination across terminals 1 and 2 of the electrical connectors for connections
longer than 100 feet (31 meters).
Table 2. Recommended Grounding Practices.
7. Recommended wire routing of leadwires:
a.
Do not run high voltage ignition transformer wires
in the same conduit with the flame detector, Data
ControlBus Module™, or Remote Reset Module
wiring.
b.
Do not route flame detector, Data ControlBus
Module™, or Remote Reset Module leadwires in
conduit with line voltage circuits.
c.
Enclose flame detector leadwires without armor
cable in metal cable or conduit.
d.
Follow directions in flame detector, Data
ControlBus Module™, or Remote Reset Module
Instructions.
8. The KDM is powered from a low voltage, energy limited
source. Mount the KDM outside of a control panel when
it is protected from mechanical damage.
IMPORTANT
A 13 Vdc power supply must be used any time more
than one KDM is used. A maximum of two KDM,
Data ControlBus™ Modules or S7810B Multi-Drop
Switch Modules are allowed in any combination.
9. Maximum wire lengths:
a.
EC/RM7830A and EC/RM7850A leadwires: The
maximum leadwire length is 300 feet (91 meters)
to terminal inputs (Control, Running/Lockout
Interlock).
b.
Flame Detector leadwires: The maximum flame
sensor leadwire length is limited by the flame
signal strength.
c.
Remote Reset leadwires: The maximum length of
wire is 1000 feet (305 meters) to a Remote Reset
pushbutton.
d.
Data ControlBus Module™: The maximum Data
ControlBus Module™ cable length depends on
the number of system modules connected, the
noise conditions and the cable used. The
maximum length of all Data ControlBus Module™
interconnecting wire is 4000 feet (1219 meters).
10. Be sure loads do not exceed the terminal ratings. Refer
to the label on the relay module or to the terminal
ratings in Tables 3A, 3B, 3C and 3D.
Final Wiring Check
1. Check the power supply circuit. The voltage and
frequency tolerance must match those of the relay
module. (A separate power supply circuit can be
required for the relay module.) Add the required
disconnect means and overload protection.
2. Check all wiring circuits and complete the Static
Checkout in Table 4 or 5 before installing the relay
module on the subbase.
3. Install the relay module.
4. Restore power to the panel.
Ground type
Recommended Practice
Earth ground (subbase and
relay module).
1.
Use to provide a connection between the subbase and the control panel of the
equipment. Earth ground must be capable of conducting enough current to blow the
20A fuse (or breaker) in the event of an internal short circuit.
2.
Use wide straps or brackets to provide minimum length, maximum surface area ground
conductors. If a leadwire must be used, use 14 AWG copper wire.
3.
Make sure that mechanically tightened joints along the ground path are free of
nonconductive coatings and protected against corrosion on mating surfaces.
Signal ground (KDM, Data
ControlBus™ Module,
Communications Interface
ControlBus™ Module).
Use the shield of the signal wire to ground the device to the signal ground terminals 3(c) of
each device. Connect the shield at both ends of the daisy chain to earth ground.
Application
Recommended Wire Size
Recommended Part Numbers
Line voltage terminals
14, 16, or 18 AWG copper conductor, 600
volt insulation, moisture-resistant wire.
TTW60C, THW75C, THHN90C.
KDM
22 AWG two-wire twisted pair with
ground, or five-wire.
Belden 8723 shielded cable or
equivalent.
Data ControlBus Module™
22 AWG two-wire twisted pair with
ground, or five-wire.
Belden 8723 shielded cable or
equivalent.
Remote Reset Module
22 AWG two-wire twisted pair, insulated
for low voltage.
—
Communication Interface
ControlBus™ Module
22 AWG two-wire twisted pair with
ground.
Belden 8723 shielded cable or
equivalent.
13 Vdc full-wave rectified
transformer power input
18 AWG wire insulated for voltages and
temperatures for given application.
TTW60C, THW75C, THHN90C.