Start-Up; Unit Start Up Cooling Mode; Unit Start Up Heating Mode; Commissioning - Bosch QV Series Installation, Operation And Maintenance Manual

26 | Start-up

Operating limits listed in the Unit Starting
Conditions section are not suitable for
continuous operating conditions. Assume
that such start-up conditions are for the
purpose of bringing the building space up to
occupancy temperature.
START-UP
Use the procedure below to initiate a proper
start-up.
DANGER: ELECTRICAL SHOCK Disconnect
switch is only to be closed when the
electrical box cover is secured to electrical
box and all exterior panels are secured on
the unit.
1. Restore power to system.
2. Turn thermostat fan position to ON. Blower
should start.
3. Balance airflow at registers.
4. Adjust all valves to the full-open position and
turn on the line power to the heat pump unit.
5. Operate unit in the cooling cycle first, then the
heating cycle for unit operating limits. Allow 15
minutes between cooling and heating tests for
pressure to equalize.

Unit Start Up Cooling Mode

1. Adjust the unit thermostat to the warmest
position. Slowly reduce the thermostat
position until the compressor activates.
2. Check for cool air delivery at unit grille a few
minutes after the unit has begun to operate.
3. Verify that the compressor is ON and that the
water flow rate is correct by measuring
pressure drop through the heat exchanger
using P/T plugs.
4. Check elevation and cleanliness of the
condensate lines; any dripping could be a sign
of a blocked line. Be sure the condensate trap
includes a water seal.
5. Check the temperature of both supply and
discharge water.
6. Check air temperature drop across the coil
when compressor is operating. Air
temperature drop should be between 15° and
25°F.
8733829041 (2021/07)

Unit Start Up Heating Mode

Operate the unit in heating cycle after
checking the cooling cycle. Allow five
minutes between tests for the pressure or
reversing valve to equalize.
1. Turn thermostat to lowest setting and set
thermostat switch to HEAT position.
2. Slowly turn the thermostat to a higher
temperature until the compressor activates.
3. Check for warm air delivery at the unit grille
within a few minutes after the unit has begun
to operate.
4. Check the temperature of both supply and
discharge water. If temperature is within
range, proceed. If temperature is outside the
range, check the heating refrigerant pressures.
5. Once the unit has begun to run, check for warm
air delivery at the unit grille.
6. Check air temperature rise across the coil
when compressor is operating. Air
temperature rise should be between 20°F and
30°F after 15 minutes load.
7. Check for vibration, noise, and water leaks.

COMMISSIONING

Record all system vitals using the "checkout sheet"
and keep with equipment. (See page #60.)
Subject to change without prior notice
QV Series Heat Pumps
QV Series Heat Pumps