Post-Installation System Checkout
8 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 duct work has been properly fastened to supply
and return duct collars.
11. Make sure return air filters are positioned correctly in the
filter rack if removed during installation.
9 Pre-Start-Up
9.1 Checking Pulley Alignment and Belt Tensioning
Before starting the unit, check the belt tension and alignment.
Even though factory-supplied drives are shipped aligned and
tensioned, their condition may have changed during transport,
storage, or installation.
Refer to the instructions found in the maintenance section of this
manual fo
r details. (See 15.7 Pulley Alignment and Belt
Tension
ing Procedure on page 35.)
9.2 Checking Scroll Compressor Rotation
Scroll compressors, like the ones used on the EC series, are
phase sensitive. When out of phase, the compressors will run in
reverse. After a few minutes of reverse operation, the
compressor internal overload protection will open, activating the
unit lockout. (This requires a manual reset. To reset, power cycle
the unit.)
NOTICE
A compressor running in reverse has a noisier than normal
operation and a lower current draw than its rated value.
This means that for proper operation, the correct direction of
rotation must be ensured. The most accurate way to ascertain
this is through the use of gauges. Follow the steps below when
using gauges:
1. Connect service gauges to the suction and discharge
pressure fittings.
2. Energize the compressor.
The suction pressure should drop and the discharge pressure
should ri
se, as is normal on any start up. If the suction pressure
does not drop and the discharge pressure does not rise to normal
levels, follow the steps in 9.2.1 Correcting Direction of Rotation.
Alternati
vely, in locations with multiple units attached to the
same bran
ch circuit, where it is not feasible to place pressure
gauges on all of them, and several units are determined to be
phased incorrectly:
1. Install pressure gauges and a phase rotation meter on one
system to serve as a baseline.
2. Check the remaining systems with the phase rotation meter.
3. Follow the steps in 9.2.1 to make corrections.
9.2.1 Correcting Direction of Rotation
If you determine that the entire job site has a concern with
electrical phasing, contact the utility company to ensure
phasing is corrected.
1. Turn OFF power to the unit. (Always follow your Lock-out/
Tag-out procedure.)
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 norm
al start-up levels.
9.3 Operating Limits
9.3.1 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.
9.3.2 Power Supply
A voltage variation of ± 10% of nameplate utilization voltage is
acceptabl
e.
9.3.3 Unit Starting Conditions
Minimum ambient temperature for heating operation is 50°F.
Minimum e
ntering air for heating is 50°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.
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EC Series Heat Pumps — 8733841499 (2024/05)
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