Cabinet Insulation; Check-Out Procedures; Pre-Start-Up Checks; Check Blower Operation - Lennox Merit CBX25UHV Installation Instructions Manual

Merit cbx25uhv (-10) series units

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Table of Contents

Enlarged version

#4 Pins Jumpered

A- Motor runs at 50% for 30 seconds.

B- Motor then runs at 82% for approximately 7-1/2

minutes. If demand has not been satisfied after 7-1/2

minutes,

C- Motor runs at 100% until demand is satisfied.

D- Once demand is met, motor runs at 50% for 30

seconds.

E- Motor ramps down to stop.

7 1/2 MIN

OFF

82% CFM

1/2 MIN

50% CFM

COOLING DEMAND

Check-Out Procedures

NOTE - Refer to outdoor unit installation instructions for

system start-up instructions and refrigerant charging

instructions.

PRE‐START‐UP CHECKS

●

Is the air handler properly and securely installed?

●

If horizontally configured, is the unit sloped up to 5/8"

toward drain lines?

●

Will the unit be accessible for servicing?

●

Has a secondary (auxiliary) pan been provided under

the unit with separate drain for units installed above a

finished ceiling or in any installation where condensate

overflow could cause damage?

●

Have ALL unused drain pan ports been properly

plugged?

●

Has the condensate line been properly sized, run,

trapped, pitched and tested?

●

Is the duct system correctly sized, run, sealed and

insulated?

●

Have all cabinet openings and wiring been sealed?

●

Is the indoor coil factory‐installed TXV properly sized

for the outdoor unit being used?

●

Have all unused parts and packaging been disposed

of properly?

●

Is the filter clean, in place and adequately size?

●

Is the wiring neat, correct and in accordance with the

wiring diagram?

●

Is the unit properly grounded and protected (fused)?

●

Is the thermostat correctly wired and in a good

location?

●

Are all access panels in place and secure?

CHECK BLOWER OPERATION

●

Set thermostat to FAN ON.

●

The indoor blower should come on.

100%

OFF

CFM

1/2 MIN

50% CFM

CHECK COOLING OPERATION

●

Set

thermostat

(approximately 5ºF lower than the indoor ambient

temperature).

●

The outdoor and indoor units should come on

immediately.

●

Check the airflow from a register to confirm that the

system is moving cooled air.

●

Set the thermostat 5ºF higher than the indoor

temperature. The indoor blower and outdoor unit

should cycle off. Air handler should cycle off 45

seconds after the outdoor unit shuts off.

CHECK ELECTRIC HEATER (IF USED)

●

Set thermostat to call for auxiliary heat (approximately

5°F above ambient temperature). The indoor blower

and auxiliary heat should come on together. Allow a

minimum of 3 minutes for all sequencers to cycle on.

●

Set the thermostat so that it does not call for heat.

Allow up to 5 minutes for all sequencers to cycle off.

Maintenance

Do not operate system without a filter. A filter is required

to protect the coil, blower, and internal parts from exces

sive dirt and dust. The filter is placed in the return duct

by the installer.

●

Inspect air filters at least once a month and replace or

clean as required. Dirty filters are the most common

cause of inadequate heating or cooling performance.

●

Replace disposable filters. Cleanable filters can be

cleaned by soaking in mild detergent and rinsing with

cold water.

●

Install new/clean filters with the arrows on the side

pointing in the direction of airflow. Do not replace a

cleanable (high velocity) filter with a disposable (low

velocity) filter unless return air system is properly sized

for it.

●

If water is seen dripping from the secondary drain line,

contact a qualified service technician. This is a sign of

a problem which must be investigated and corrected.