Post-Installation System Checkout; Pre-Start-Up; Air Coil; Scroll Compressor Rotation - Bosch QV Series Installation, Operation And Maintenance Manual

QV Series Heat Pumps
POST-INSTALLATION SYSTEM
CHECKOUT
After completing the installation and before
energizing the unit, the following system checks
MUST be made:
1. Verify that the supply voltage to the heat pump
is in accordance with the nameplate ratings.
2. Make sure that all electrical connections are
tight and secure.
3. Check the electrical fusing and wiring for the
correct size.
DANGER: Ensure the cabinet and electrical
box are properly grounded.
4. Verify that the low-voltage wiring between the
thermostat and the unit is correct.
5. Verify that the water piping is complete and
correct.
6. Check that the water flow is correct and adjust
if necessary.
7. Check the blower for free rotation and that it is
secured to the shaft.
8. Verify that vibration isolation has been
provided.
9. Confirm that all access panels are secured in
place.
10. Verify that the blower support has been
removed.
11. Verify that duct work has been properly
fastened to supply and return duct collars.
12. Make sure return air filters are positioned
correctly in the filter rack if removed during
installation.

PRE-START-UP

Air Coil

To obtain maximum performance, clean the air coil
before starting the unit. A 10% solution of
dishwasher detergent and water is recommended
for both sides of the coil. Rinse thoroughly with
water.

Scroll Compressor Rotation

It is important to be certain that the compressor is
rotating in the proper direction. To determine
whether or not compressor is rotating in the
proper direction see as follows:
QV Series Heat Pumps
1. Connect services gases to suction and
discharge pressure fittings.
2. Energize the compressor.
3. The suction pressure should drop and the
discharge pressure should rise, as is normal on
any start up.
If the suction pressure does not drop and the
discharge pressure does not rise to normal levels:
1. Turn off power to the unit. Install disconnect
tag.
2. Reverse any two of the unit power leads.
3. Reapply power to the unit and verify pressures
are correct.
The suction and discharge pressure levels should
now move to their normal start-up levels.
When the compressor is rotating in the wrong
direction, the unit makes more noise and does not
provide cooling. After a few minutes of reverse
operation, the scroll compressor internal overload
protection will open, activating the unit lockout.
This requires a manual reset.
To reset, turn the thermostat on and then off.
There is a five-minute time delay before the
compressor will start.

Operating Limits

Environment
This equipment is designed for indoor installation
only. Extreme variations in temperature, humidity,
and corrosive water or air will adversely affect the
unit performance, reliability and service life.
Power Supply
A voltage variation of ± 10% of nameplate
utilization voltage is acceptable.
Unit Starting Conditions
Minimum ambient temperature for heating
operation is 45°F. Minimum entering air for heating
is 40°F. Minimum entering water temperature for
heating with standard range units is 50°F and for
extended range units is 20°F. Air and water flow
rates must be within the cataloged range.
Subject to change without prior notice

Post-Installation System Checkout | 25

8733829041 (2021/07)