Panasonic CS-W50BTP Service Manual page 62

(*2)
Outdoor unit fan control during heating mode operation
When the compressor is on during heating mode operation (except during defrosting and when the liquid bypass valve is on), the
outdoor unit fan is controlled by means of input (CN2) indicating whether the contact of the heating pressure switch on the outdoor
unit circuit board is open or closed.
(At the start of heating mode operation, the fan operates at HI speed.)
26.4. Hot starting
1. When heating mode operation starts
a. Start
Hot start control commences when heating mode operation starts.
b. Operation
"PREHEAT" appears on the remote control display. (Other displays remain unchanged.)
The indoor unit fan stops. In addition, during hot starting, the louvre stays at the horizontal position (angle 0°).
c. Cancelling
Hot starting will be cancelled when the compressor is turned on or the indoor unit pipe temperature sensor is 18°C or higher
or after 1 minute of operation.
After cancellation, the "PREHEAT" display on the remote control disappears and the louvre operation returns to the previous
setting.
(However, for 2 minutes after cancellation, the indoor unit fan operates at LOW speed, and then returns to the previous
setting.)
<When hot start operation is cancelled by temperature>
62