Trane WC-IOM-7 manual Pre-Start, Test Modes, Service test guide for component operation

Pre-Start

Test Modes

There are three methods in which the “Test” mode can be cycled at LTB-Test 1 and LTB-Test 2.

1.Step Test Mode - This method initiates the different components of the unit, one at a time, by temporarily shorting across the two test terminals for two to three seconds.

For the initial start-up of the unit, this method allows the technician to cycle a component “On” and have up to one hour to complete the check.

2.Resistance Test Mode - This method can be used for start-up providing a decade box for variable resistance outputs is available. This method initiates the different components of the unit, one at a time, when a specific resistance value is placed across the two test terminals. The unit will remain in the specific test mode for approximately one hour even though the resistance is left on the test terminals.

3.Auto Test Mode - This method is not recommended for start-up due to the short timing between individual component steps. This method initiates the different components of the unit, one at a time, when a jumper is installed across the test terminals. The unit will start the first test step and change to the next step every 30 seconds. At the end of the test mode, control of the unit will automatically revert to the applied "System" control method.

For unit test steps, test modes, and step resistance values to cycle the various components, refer to Table 5.

Table 5.		Service test guide for component operation
TEST				Econ
STEP		MODE	Fan	(Note 2)	Comp 1	Comp 2	Heat 1	Heat 2	Ohms
1		Fan	On	Minimum	Off	Off	Off	2.2K
				Position Off
				Setpoint 0%
		Minimum	On	Selectable	Off	Off	Off	Off
		Ventilation
2		Economizer	On	Open	Off	Off	Off	Off	3.3K
		Test Open
3		Cool Stage 1	On	Minimum	(Note 1)	Off	Off	Off	4.7K
				Position	On
4	(Note 3) Cool Stage 2		On	Minimum	(Note 1)	(Note 1)	Off	Off	6.8K
				Position	On	On
5	(Note 3) Reheat		On	Minimum	On	On	Off	Off	33K
6	(Note 3) Heat Stage 1		On	Minimum	Off	Off	On	Off	10K
7	(Note 3) Heat Stage 2		On	Minimum	Off	Off	On	On	15K

Notes:

1 - The condenser fans will operate any time a compressor is "On" providing the outdoor air temperatures are within the operating values. 2 - The exhaust fan will turn on anytime the economizer damper position is equal to or greater than the exhaust fan setpoint.

3 - Steps for optional accessories and non-applicable modes in unit will be skipped.

WC-IOM-7 • Packaged Heat Pump 35