Trane RT-SVX19A-E4 manual Economizer Set-Up, ReliaTel Control Heating Operation, Ignition Module

Operation

Economizer Set-Up

Adjusting the minimum position potentiometer located on the unit economizer Actuator (ECA) sets the required amount of ventilation air.

Two of the three methods for determining the suitability of the outside air can be selected utilizing the enthalpy potentiometer on the ECA, as described below:

1.Ambient Temperature - controlling the economizing cycle by sensing the outside air dry bulb temperature. The Table below lists the selectable dry bulb values by potentiometer setting.

2.Reference Enthalpy - controlling the economizer cycle by sensing the outdoor air humidity. The Table below lists the selectable enthalpy values by potentiometer setting.

If the outside air enthalpy value is less than the selected value, the economizer is allowed to operate.

3.Comparative Enthalpy - By utilizing a humidity sensor and a temperature sensor in both the return air stream and the outdoor air stream, the unit control processor (RTRM) will be able to establish which conditions are best suited for maintaining the zone temperature, i.e. indoor conditions or outdoor conditions. The potentiometer located on the ECA is non-functional when both the temperature and humidity sensors are installed.

Table 39 - Potentiometer Setting

Potentiometer	Dry BuIb	Enthalpy
Setting	(°C)	(KJ/kg)
A	23*	63
B	21	58
C	19	53
D	17	51

*Factory Setting

ReliaTel™ Control Heating Operation

When the system switch is set to the "Heat" position and the zone temperature falls below the heating setpoint controlband, a heat cycle is initiated when the RTRM communicates ignition information to the Ignition module (IGN).

Ignition Module

Two Stage (IGN) runs self-check (including verification that the gas valve is de-energized). (IGN) checks the high-limit switches (TC01 & TC02) for normally closed contacts. With 115 VAC power supplied to the ignition module (IGN), the hot surface ignition probe (IP) is preheated for approximately

45 seconds. The gas valve (GV) is energized for approximately

7 seconds for trial for ignition, to ignite the burner.

Once the burner is ignited, the hot surface ignition probe (IP) is de- energized by the ignition module (IGN) and functions as the flame sensing device.

If the burner fails to ignite, the ignition module will make two more attempts before locking out. The green LED will indicate a lock out by two fast flashes. An ignition lockout can be reset by:

1.Opening for 3 seconds and closing the main power disconnect switch

2.By switching the "Mode" switch on the zone sensor to "OFF" and then to the desired position

3.Allowing the ignition control module to reset automatically after one hour.

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