Specifications

11
Pre Start-Up
Prior to initial start-up, perform the following checks to ensure proper unit operation:
ELECTRICAL CHECKS
1. Check to make sure that incoming voltages
match the nameplate's phase and voltage
listings.
2. Make sure that the unit is properly grounded
to an earth ground.
3. Check all internal electrical components and
terminal blocks for loose connections, which
may have been caused by shipping
vibrations.
4. Check that all fuses are correct and securely
in the fuse blocks.
5. Check the blower motor overload for correct
setting (FLA of motor on motor nameplate)
and make sure that the overload has not
been tripped.
MECHANICAL CHECKS
1. Make sure that all direct expansion and
water/glycol isolation valves are open in the
system.
2. Check to make sure that water/glycol will
flow through the unit for heat rejection.
3. Bleed any air from the unit’s cooling system
using the internally mounted Schrader
valves.
4. Check for water leaks at the humidifier
connections.
5. Make sure that the blower belts are adjusted
correctly.
6. Before replacing the unit’s panels, make
sure that the inside of the unit, especially the
blower wheels, is free from debris.
7. Make sure that the air filters are in place and
clean.
When all of these checks have been performed,
replace and secure all of the unit's panels
Start-Up
After all mechanical and electrical service connections have been made and checked, start the unit as
follows:
1. Make sure that the power switch is in the
OFF position and apply power to the unit.
Turn unit disconnect switch to the ON
position (if applicable) and verify that line
voltage is as specified on the unit
nameplate. Check the control transformer
secondary voltage. This voltage should be a
normal 24 volts, no higher than 26.5 volts
and no lower than 23 volts.
2. Check for proper rotation of the blower
motors. If rotation is incorrect, depress
power switch to turn the unit off and shut off
the main power at the source disconnect.
Interchange any two of the three main line
power leads to the power distribution block
in the unit. Return to step one.
3. Acknowledge any alarms that appear on the
display at the controller’s prompts. The
alarms are usually power loss, high or low
temperature and high or low humidity.
4. The controller will energize heat, cool,
humidification, or dehumidification circuits as
required and display the appropriate
alphanumerical messages for the unit’s
mode of operation.
5. The operation of the unit must be checked
thoroughly. To accomplish this, the set
points on the controller must be set to
extreme conditions. Before checking
extreme points, the computer equipment
(heat load) must be installed. Depending on
the temperature and humidity in the space at
the time of installation, check either the
stages of heating or cooling, or
humidification or dehumidification modes.
6. Humidification or dehumidification can be
checked by changing the humidity set point
in a similar manner.
7. Check that all safety alarms and controls
function properly.
Complete the start-up sheet and return it to
APC.