Controls using 24 VAC

Field Installed Control Wiring

The Rooftop Module (RTM) must have a mode input in or- der to operate the rooftop unit. The flexibility of having sev- eral system modes depends upon the type of sensor and/or remote panel selected to interface with the RTM. An overall layout of the various control options available for a Constant Volume application, with the required number of conductors for each device, is illustrated in Figure 3-16. Figure 3-17 il- lustrates the various control options with the required num- ber of conductors for a Variable Air Volume application.

Note: All field wiring must conform to NEC guidelines as well as state and local codes.

The various field installed control panels, sensors, switches, and contacts discussed in this section require both AC and DC consideration. These diagrams are representative of standard applications and are provided for general refer- ence only. Always refer to the wiring diagram that shipped with the unit for specific electrical schematic and connection information.

WARNING

Hazardous Voltage!

Disconnect all electric power, including remote discon- nects before servicing. Follow proper lockout/tagout procedures to ensure the power can not be inadvert- ently energized. Failure to disconnect power before ser- vicing could result in death or serious injury.

Before installing any connecting wiring, refer to Figure 3-2 for the electrical access locations provided on the unit and Table 3-8 for AC conductor sizing guidelines, and;

a. Use copper conductors unless otherwise specified.

b. Ensure that the AC control wiring between the controls and the unit's termination point does not exceed three (3) ohms/conductor for the length of the run.

Note: Resistance in excess of 3 ohms per conductor may cause component failure due to insufficient AC voltage supply.

c. Be sure to check all loads and conductors for grounds, shorts, and miswiring.

Table 3-8

AC Conductors

Distance from Unit	Recommended
to Control	Wire Size
000 - 460 feet	18 gauge
461 - 732 feet	16 gauge
733 - 1000 feet	14 gauge

d. Do not run the AC low voltage wiring in the same conduit with the high voltage power wiring.

Installation (Continued)

Controls using DC Analog Input/Outputs

Before installing any connecting wiring between the unit and components utilizing a DC analog input\output signal, refer to the appropriate illustration in Figure 3-2 for the electrical access locations provided on the unit and

Table 3-9 for conductor sizing guidelines and;

a. Use standard copper conductor thermostat wire unless otherwise specified.

b. Ensure that the wiring between the controls and the unit's termination point does not exceed two and a half (2.5) ohms/conductor for the length of the run.

Note: Resistance in excess of 2.5 ohms per conductor can cause deviations in the accuracy of the controls.

Table 3-9

DC Conductors

Distance from Unit	Recommended
to Control	Wire Size
000 - 150 feet	22 gauge
151 - 240 feet	20 gauge
241 - 385 feet	18 gauge
386 - 610 feet	16 gauge
611 - 970 feet	14 gauge

c. Do not run the electrical wires transporting DC signals in or around conduit housing high voltage wires.

Units equipped with a Trane Communication Interface (TCI) or LonTalk Communication Interface (LCI) option which uti- lizes a serial communication link;

a. Must be 18 AWG shielded twisted pair cable (Belden 8760 or equivalent).

b. Must not exceed 5,000 feet maximum for each link.

c. Must not pass between buildings.

Constant Volume System Controls

Remote Panel w/o NSB (5U56) - BAYSENS010B

This electronic sensor features four system switch settings (Heat, Cool, Auto, and Off) and two fan settings (On and Auto) with four system status LED's. It is a manual or auto- matic changeover control with dual setpoint capability. It can be used with a remote zone sensor BAYSENS017B. Refer to Table 3-10 for the Temperature vs Resistance coefficient.

Remote Panel w/ NSB (5U58) - BAYSENS019*

This 7 day programmable sensor features four periods for Occupied\Unoccupied programming per day. If the power is interrupted, the program is retained in permanent memory. If power is off longer than 2 hours, only the clock and day may have to be reset.

The six programming keys located on the front panel allows selection of four system modes (Heat, Cool, Auto, and Off), two fan modes (On and Auto). It has dual temperature se- lection with programmable start time capability.

Hazardous Voltage!