Bard W12A2-A Manuel D’Utilisation

Manual 2100-509E 

Page 

14 of 17

For improved start up performance, wash the indoor coil 
with a dishwasher detergent.

  1.  Caution owner to maintain clean air filters at all 

times.  Also not to needlessly close off supply and 

return air registers.  This reduces airflow through the 
system which shortens equipment service life as well 
as increasing operation costs.

  2.  The unit is equipped with a high pressure cut out 

switch.

  3.  Check all power fuses or circuit breakers to be sure 

they are the correct rating.

  4.  Periodic cleaning of the outdoor coil to permit full 

and unrestricted airflow circulation is essential.

The W12Aà models are supplied with a remote reset 
high and low pressure switch.  If tripped, this pressure 
switch may be reset by turning the thermostat off then 
back on again.

HEATING – Circuit R-Y makes at thermostat pulling 
in compressor contactor, starting the compressor 
and outdoor motor.  The G (indoor motor) circuit 
is automatically completed on any call for cooling 
operation or can be energized by manual fan switch 
on subbase for constant air circulation.  On a call for 
heating, circuit R-W1 make at the thermostat pulling in 
heat contact for the strip heat and blower operation.

The compressor control module is optional on the 
models covered by this manual.  The compressor control 
is an anti-short cycle/lockout timer with high and low 
pressure switch monitoring and alarm relay output.

Adjustable Delay on Make and Break Timer
On initial power up or any time power is interrupted to 
the unit the delay on make period begins, which will be 
2 minutes plus 10% of the delay on break setting.  When 
the delay on make is complete and the high pressure 
switch (and low pressure switch if employed) is closed, 
the compressor contactor is energized.  Upon shutdown 
the delay on break time starts and prevents restart until 
the delay on break and delay on make periods have 
expired.

During routine operation of the unit with no power 
interruptions the compressor will operate on demand 
with no delay.

High Pressure Switch and Lockout Sequence
If the high pressure switch opens, the compressor 
contactor will de-energize immediately.  The lockout 
timer will go into a soft lockout and stay in soft lockout 
until the high pressure switch closes and the delay on 
break time has expired.  If the high pressure switch opens 
again in this same operating cycle the unit will go into 
manual lockout condition and the alarm relay circuit 
will energize.  Recycling the wall thermostat resets the 
manual lockout.

Sequence
If the low pressure switch opens for more than 120 
seconds, the compressor contactor will de-energize 
and go into a soft lockout.  Regardless the state of the 
low pressure switch, the contactor will reenergize after 
the delay on make time delay has expired.  If the low 
pressure switch remains open, or opens again for longer 
that 120 seconds, the unit will go into manual lockout 
condition and the alarm relay circuit will energize.  
Recycling the wall thermostat resets the manual lockout.

Alarm Relay Output
Alarm terminal is output connection for applications 
where alarm relay is employed.  This terminal is powered 
whenever compressor is locked out due to HPC or LPC 
sequences as described.