Honeywell High Voltage RTP Cable (1.0M, 3.28ft.) Note 6 (NOT FOR SIL2 SYSTEMS) 900RTC-H110
Remote Termination Panel (RTP)
The optional Remote Termination Panel (RTP) provides an easy way to connect the HC900 controller to
the field wiring. The RTP integrates some of the typical externally connected components, reducing wiring
and setup time. It also minimizes the need for multiple wires under a single screw connection by
expanding the connectivity of the shared terminals of the I/O modules.
See Appendix - Installation of Remote Termination Panels (RTPs) page 217 for details.
Terminal Block-to-Field (Signal) Wiring
Although both of the two available terminal block styles can be used on all I/O module types, wiring
methods vary with the module type and with the type of field devices connected to the terminal block. The
descriptions that follow provide details.
Wiring can be routed through the terminal block at the top, at the bottom, or both. Wiring should be fixed
in place using wire ties at the slotted tabs that are molded in at top and bottom of each terminal block.
Wiring Rules and Recommendations
In general, stranded copper wire should be used for non-thermocouple electrical connections. Twisted-pair
wiring with shielded cable is recommended and will improve noise immunity if wire routing is suspect.
Wire Gage
Observe all local codes when making power connections. Unless local electrical codes dictate otherwise,
the recommended minimum wire size for connections is given in Table 12.
Table 12 – Minimum Recommended Wire Sizes
Wire
Gauge
Wire Application
14 Earth ground to common power supply.
14 to 16 AC to power supply
10 to 14 Earth ground wire
20 DC current and voltage field wiring
22 DC current and voltage wiring in control room
Routing and Securing Wires
Typically, field wiring is routed to connections at a terminal panel near the controller and then from the
terminal panel to the terminal blocks on the I/O modules.
Whatever method of routing is used, wiring must be mechanically supported along its length, and must be
protected from physical damage and electromagnetic (noise) interference. (See Electrical Considerations
page 56.)
Also, all wires must be securely terminated, using appropriate wiring practices.

Signal Grounding (
Figure 39)
The shield for each input should be grounded
at the grounding bar (optional) at the top or
bottom of each rack as indicated in Figure 40.
For low-frequency noise rejection, I/O wiring
shields should be grounded only at the
controller end.
For high-frequency noise rejection, shields
should be grounded at the controller and at
the field device. If the ground voltage
potential at the field device is different from
that at the controller, a DC isolation capacitor
should be used between the shield and the
grounding bar on the rack.
Figure 39 – Signal-Wire Grounding
Aluminum grounding bars for I/O wiring are available as options. When selected for use, they are fastened
to the top and/or bottom of each rack, as indicated in Figure 40. To enable connection of multiple ground
wires with a single screw, the wires can be twisted together and secured with a wire lug.
To facilitate module replacement, it is advisable in most cases to route all wiring through either the top or
the bottom of the terminal block. This
allows the terminal block to pivot up or
down, allowing ready access to the
module, and is the preferred method
for a limited number of wires.
For a larger number of wires, or for
wires of a heavier gauge, it is advisable
to route some wires through the top of
the terminal block, and some through
the bottom, as indicated in Figure 40.
In this case, it is necessary to adjust
wire length so as to ensure adequate
flexibility of the twisted wires and to
provide clearance sufficient to remove
the I/O module.
Terminal Block Jumper Combs
Two styles of terminal block jumper combs are available for use with the barrier-style terminal blocks: ten position and two position. (Figure 41)
The ten-position jumpers are used with AC
output modules to inter-connect L1 (AC Hot) of
all channels.
The two-position jumpers are used to connect
Common (DC negative or AC neutral) for the DC
input module, the DC Output Module, and the
AC Input Module. Each of these module types
has groups of eight channels, with the two groups
isolated from each other. The two-position
jumper connects (Common) terminals 10 and 12,
making one group of sixteen non-isolated
channels.
The two-position jumper can also be used to
connect the V+ terminals on the DC Output
Module.
Refer to the wiring information on each module,
given in this section of this manual.