Bard CH3S1, CH4S1, CH5S1 installation instructions Manual, 2100-455M, Page, 20 of

There is an initiate defrost jumper (sen jump) on the control that can be used at any outdoor ambient during the heating cycle to simulate a 0° coil temperature.

This can be used to check defrost operation of the unit without waiting for the outdoor ambient to fall into the defrost region.

By placing a jumper across the SEN JMP terminals (a

¼inch QC terminal works best) the defrost sensor mounted on the outdoor coil is shunted out & will activate the timing circuit. This permits the defrost cycle to be checked out in warmer weather conditions without the outdoor temperature having to fall into the defrost region.

In order to terminate the defrost test the SEN JMP jumper must be removed. If left in place too long, the compressor could stop due to the high pressure control opening because of high pressure condition created by operating in the cooling mode with outdoor fan off. Pressure will rise fairly fast as there is likely no actual frost on the outdoor coil in this artificial test condition.

There is also a 5-minute compressor time delay function built into the HPC. This is to protect the compressor from short cycling conditions. The board’s LED will have a fast blink rate when in the compressor time delay. In some instances, it is helpful to the service technician to override or speed up this timing period, and shorting out the SPEEDUP terminals for a few seconds can do this.

Low Pressure Switch Bypass Operation - The control has a selectable (SW1) low pressure switch bypass set up to ignore the low pressure switch input during the first (30, 60, 120 or 180 seconds) of “Y” operation.

After this period expires, the control will then monitor the low pressure switch input normally to make sure that the switch is closed during “Y” operation.

High Pressure Switch Operation - The control has a built-in lockout system that allows the unit to have the high pressure switch trip up to two times in one hour and only encounter a “soft” lockout. A “soft” lockout shuts the compressor off and waits for the pressure switch to reset, which at that point then allows the compressor to be restarted as long as the 5-minute short cycle timer has run out. If the high pressure switch trips a third time within one hour, the unit is in “hard” lockout indicating something is certainly wrong and it will not restart itself.

Manual	2100-455M
Page	20 of 28