AAF AV Installation guide

AAF@ OPERATION AND
MAINTENANCE DATA
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MODEL AV FLOOR MOUNTED
MODEL AH CEILING MOUNTED
SPLIT SYSTEM ASHP UNIT VENTILATOR
100% OUTDOOR AIR MODEL
WHAT IS AUNIT VENTILATOR?
Your unit ventilator can be classified as akind of classroom
“thermal handy man.” Unit ventilators maintain aclean, com-
fortable, healthy environment automatically. They heat, ven-
tilate and provide natural cooling (with outdoor air) or
mechanical cooling.*
Your room temperature should be neither too hot nor too
cold. The unit ventilator provides just the right amount of pro-
perly conditioned air to meet the needs of various types of
activity throughout the day.
If the air being discharged by the unit feels cold to your
hand, it is because the room needs this cooling effect to pre-
vent overheating.
Please observe these simple rules to
assure efficient operation of your unit
ventilator.
1.Keep doors and windows closed to allow the unit to
function properly.
2. DO NOT attempt to adjust the unit thermostat. Ask
the custodian or other authorized person to make
adjustments if needed.
*Refrigeration cooling is used instead of outdoor air during
warm weather.
HOW YOUR UNIT VENTILATOR WORKS
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6
SOMETIMES YOUR UNIT VENTILATOR WILL BE
SENDING HEATED ROOM AIR INTO YOUR CLASS-
ROOM USUALLY THIS OCCURS BEFORE OCCU-
PANCY
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9693
6
SOMETIMES YOUR UNIT VENTILATOR WILL BE
SENDING AMIXTURE OF ROOM AIR AND FRESH
OUTDOOR AIR INTO YOUR CLASSROOM THIS
USUALLY OCCURS INTERMITTENTLY ALL DAY
LONG
,2
,
86
“SOMETIMES YOUR UNIT VENTILATOR WILL BE
SENDING ONLY FRESH, OUTDOOR AIR INTO YOUR
CLASSROOM TO COOL THE ROOM, COUNTER-
ACTING THE HEAT GENERATED BY THE PUPILS,
LIGHTS AND SUN THIS ALSO MAY OCCUR INTER-
MITTENTLY ALL DAY LONG
OPERATION
GENERAL —The model AV and AH ASHP features asplit
system refrigeration system to provide both heating and cool-
ing. The unit is also capable of providing free cooling by
automatically delivering up to 100% outdoor air. Please read
this bulletin carefully. It is important to understand how the
unit operates. Aproperly maintained unit should provide years
of troublefree service.
UNIT OPERATION —Place the main power “on-off” switch,
accessible behind the center front access panel (see Figure
1), in the “On” position. This switch should remain in the “On”
position except when servicing the unit or when the unit is
to be shut down for an extended period,
ROOM AIR FANS —The room air fans will run continuously
during the occupied period. During the unoccupied period
(night setback), the fans will run only on a call for heat or cool-
ing. NOTE: When the unit is not furnished with any type of
night setback arrangement, the fan will run continuously
unless the unit is manually turned off.
COOLING —Mechanical cooling is provided by aconven-
tional sealed refrigeration system whereby heat from the room
is absorbed by the refrigerant in the indoor coil and, through
the action of the compressor, is transferred to the outdoor coil.
The unit is capable of bringing in up to 100% outside air to
cool the room. Therefore, the refrigeration system only
operates during those periods when the outside temperature
is too warm to cool the room.
HEATING —The refrigeration system includes a“reversing
valve” which can reverse the operation of the refrigeration
system so that heat from the outside air is absorbed by the
refrigerant in the outdoor coil and transferred to the indoor
coil where it is used to heat the room. This is “Reverse-Cycle
Refrigeration” or “Heat Pump” mode of operation.
0 1991 SnyderGeneralCorporation

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OPERATION (CONTINUED)
Whenever heating is required, the unit operates as aheat rapidly and causes the frost to melt, During the defrost cycle
pump. As long as it is possible to maintain the desired room electric heat is energized in steps as required to avoid un-
temperature, only the reverse-cycle refrigeration operates, comfortably low discharge air temperature into the room.
However, when additional heating is required, an electric Under certain atmospheric conditions the initiation of the
resistance coil is activated in stages to supplement the heat defrost cycle will cause a“puff” or larger quantity of water
produced by the reverse cycle system. vapor to be released to the outside, The characteristic sound
NOTE: The microprocessor software program prevents the of the reversing valve will also be heard when the defrost cy-
operation of the electric resistance heat when the outdoor cle starts and stops. These phenomena are normal events
temperature is above 20° Fexcept during defrost cycle or if and should cause no alarm.
the emergency electric heat switch is in the emergency heat
position. UNOCCUPIED (OPTIONAL) —During the unoccupied period
the unit is turned off by the network software on network units
DEFROST —When the unit is in the heating mode, the out- or on stand-alone units by the optional unit mounted timeclock
door coil may operate at temperatures low enough to form or by de-energizing the control circuit through aremote device
frost on the outdoor coil, The frost will tend to block the flow such as atimeclock or manual switch.
of air through the outdoor coil and reduce the efficiency of The unit will remain off unless the room temperature falls
the machine. The unit has an automatic defrost cycle, Dur- below the unoccupied setback temperature or rises above the
ing the defrost cycle, the refrigeration system operates in the unoccupied setup temperature. The outdoor air damper re-
tooling mode except with the outdoor fan off. With the out- mains closed during the unoccupied period.
door fan off, the temperature of the outdoor coil increases
CONTROLS
Figure 1. Front view with access panels removed
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1. MicroTechUnit Ventilator Controller 6. “High-Off-Low” Motor Speed Switch 10. Terminal Strips
2. Room Temperature Adjustment 7. Tenant Override Switch (Optional on AV)
3. Damper Actuator 11. Emergency Electric Heat Switch
*8. Holiday Switch (Optional) 12. Right End Compartment
4. Sampllng Chamber T8 Day/Night Switch (Optional on AV) 13. Left End Compartment
*5. Timeclock (Optional) 9. Unit Main Power “On-Off” Switch 14. Electric Connection Box
tNot furnished with network units since the function is handled through the communication network.
MICROTECH UNIT VENTILATOR CONTROLLER —This is
afactory mounted microprocessor-based DDC control device
which is capable of stand-alone control or network control from
afront end computer. The controller can support sixteen (16)
inputs and sixteen (16) outputs. Each input supports either
analog sensing and/or binary contact closure. Each output
consists of abinary contact closure to operate controlled
devices. The controller will provide status of either the out-
puts or the inputs upon request from apersonal computer
connected either to network or an individual controller. The
controller contains self-diagnostic capability to maintain con-
stant reliability. The controller provides heating and cooling
control in response to various inputs as well as the room sen-
sor which may be either unit mounted or wall mounted.
2
Damper actuators are precisely positioned by means of step-
and-wait parameters built into control software. Two-position
functions such as DX cooling/heating and electric heating are
also initiated by the controller. Room temperature adjustment,
unoccupied temperature offset and outdoor air damper
minimum position are all adjustable at the controller. In anet-
work system, these three adjustments are not operative and
are done as part of the network control plan. See Figure 1.
The controller provides avisual means of fault detection
with the use of astatus LED on board.
ROOM TEMPERATURE ADJUSTMENT —This item controls
the room temperature setpoint. Adjust the room temperature
to the desired setting (maybe unit mounted or wall mounted;

CONTROLS (CONTINUED)
see Figure 1for unit mounted). To readjust the temperature
setting move the dial in small increments and allow at least
one hour to elapse before adjusting again. It is important to
understand that the unit may be discharging cool air even
during the heating season in order to prevent overheating of
the space. Adjustment of the temperature setting should be
based on the actual temperature of the space and not the
temperature of air discharging from the unit. In anetwork
system, this adjustment is not operative and is done as
part of the network control plan.
DAMPER ACTUATOR —This device positions the outdoor
and room air dampers in response to the unit ventilator con-
troller. It is factory mounted, wired and adjusted. See Figure 1.
SAMPLING CHAMBER —This enclosure houses the room
air sensor whenever aunit mounted sensor is specified. Room
air is continuously drawn through the sampling chamber to
insure fast, accurate response to temperature changes within
the room, See Figure 1.
TIMECLOCK (OPTIONAL) —This device automatically
cycles unit through occupied and unoccupied modes in ac-
cordance with auser programmed time schedule. Program-
ming instructions are included. The timeclock has battery
back-up so it will not require resetting if electric power is in-
terrupted. It is located in front of the room air fan motor. See
Figure 1. It is not furnished with network units since the
function is handled through the communication network.
“HIGH-OFF-LOW” MOTOR SPEED SWITCH —This switch
is provided so that the user may select the fan speed desired.
For maximum heating or cooling capacity, depress the “High”
button. For location see Figure 1. Model AH unit may be fur-
nished with wall mounted motor speed switch. Model AH unit
with high external static will operate on high speed only. The
“Off” position shuts unit down completely.
TENANT OVERRIDE SWITCH (OPTIONAL) —Allows the
user to manually override the unit’s unoccupied mode for up
to apre-programmed two hours. The tenant override value
is resettable from apersonal computer connected either to
network or an individual controller. The tenant override can
also be part of the wall room sensor. See Figure 1.
HOLIDAY SWITCH (OPTIONAL) —This device is furnished
with the optional timeclock. It permits manual changeover to
unoccupied (night) control for extended or otherwise un-
scheduled periods. The switch must be manually returned to
the normal (automatic control) position at the end of the “holi-
day” period for unit to operate on the automatic temperature
control sequence. For location see Figure 1. Not furnished
with network units since the function is handled through
the communication network.
DAY/NIGHT SWITCH (OPTIONAL) —This manual switch
may be used in lieu of automatic unoccupied (night) control
or remote unoccupied control. It permits manual changeover
to unoccupied control, but must be manually returned to the
‘rDay” position for unit to operate on the automatic control
sequence.
UNIT MAIN POWER “ON-OFF” SWITCH —Disconnects
main power to unit for servicing the unit or when unit is to
be shut down for an extended period.
TERMINAL STRIPS —Provide convenient field connection
points for wall mounted room sensor and heat pump control
circuit. Refer to wiring diagram for details. See Figure 1.
EMERGENCY ELECTRIC HEAT SWITCH —Should the
reverse cycle heating system become inoperative, this device
allows the unit to be manually switched to emergency elec-
tric heat. This will permit the electric resistance heaters to
operate as needed regardless of outdoor temperature.
IMPORTANT WHEN THE PROBLEM HAS BEEN REPAIRED
AND THE REVERSE CYCLE HEATING SYSTEM IS AGAIN
OPERATIONAL, THE EMERGENCY ELECTRIC HEAT
SWITCH MUST BE RETURNED TO “NORMAL” IN ORDER
TO PROVIDE THE MOST ECONOMICAL OPERATION.
ELECTRIC CONNECTION BOX —Contains the motor speed
switch, motor speed transformer, and fusetron(s). Wiring con-
nections to the day/night relay and vent relay are made in this
box. Refer to the unit wiring diagram for specifics. See Figure
1.
SEQUENCE OF OPERATION
Also refer to the installation and maintenance bulletin for the MicroTech controller for addi-
tional control information and unit sequence of operation.
WALL MOUNTED ROOM AIR TEMPERATURE SENSORS
In addition to the unit mounted room air temperature sensor,
the following are the choices of wall mounted room air
temperature sensors available:
1.
2
3.
Wall Sensor. This provides athermistor type temperature 4,
sensing for the UVC.
Wall Sensor With Tenant Override. This provides ther-
mistor type temperature sensing, an LED unit mode in-
dicator, and a tenant override switch to allow timed over-
ride from unoccupied to occupied mode.
Wall Sensor With Tenant Override and Setpoint Adjust-
ment. This provides thermistor type temperature sensing,
an LED unit mode indicator, atenant override switch to
allow timed override from unoccupied to occupied mode,
and a setpoint offset adjustment potentiometer which
allows the user to increase or decrease the current con-
trol setpoint by 3F.
Wall Sensor With Tenant Override, Setpoint Adjustment
and Communications Port. This provides thermistor
temperature sensing, an LED unit mode indicator, atenant
override switch to allow timed override from unoccupied
to occupied mode, asetpoint offset adjustment poten-
tiometer which allows the user to increase or decrease the
current control setpoint by 3° F, and an RS-232 com-
munications port to allow aportable PC with Monitor soft-
ware to connect to the unit or network.
3

ROUTINE MAINTENANCE —MODEL AV FLOOR UNITS
FILTERS —Units are shipped with throwaway filters in-
stalled. To insure troublefree operation filters must be renew-
ed or cleaned on a regular basis. DO NOT NEGLECT! To ser-
vice filter, push “Off” button and remove middle front panel
with 5/32 hex head wrench (see Figure 2).
TYPES OF FILTERS —All types of filters should be check-
ed at least once amonth or more frequently in areas with
high dust or lint content.
1.Throwaway –(Glass fiber media in disposable cardboard
frame.) Replace as required.
2. Permanent —(Metal media with metal frame.) Immerse
and agitate in hot cleaning solution: 11/2pounds washing
soda to each 10 gallons of water. Drain and dry. Spray or
dip in filter oil and drain thoroughly.
3. Renewable —(Glass fiber media in metal frame.) Remove
filter pad from the frame and discard. Replace with glass
throwaway media cut to the proper size.
FIGURE2./“ I
ACCESS TO MOTOR FOR OILING IS THROUGH
RIGHT FRONT ACCESS PANEL OR BY REMOV-
ING GRILLE
NOTE: Use of synthetic filter media is NOT RECOMMENDED.
OILING –Once every year add 3 drops of SAE 20 or 30
weight NON-DETERGENT oil to each of the two oil holes
(Figure 3) on the fan motor and fill the fan shaft bearing cup
(Figure 4) at the opposite end of the fan shaft. Access to the
oil points can be gained by removing the discharge grille with
acrosspoint screwdriver.
CLEANING —The exterior cabinet surface should be kept
clean and waxed. The fans and fan housings should be kept
clean. This can be accomplished by removing the discharge
grille with acrosspoint screwdriver (see Figure 5). Oiling the
fan motor and fan shaft bearings can also be accomplished
at this time.
IMPORTANT: AIR VENT OPENINGS IN THE FAN MOTOR
MUST BE KEPT CLEAR.
FIGURE3,
FANMOTOR
OIL HERE
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FIGURE4.
LEFT VIEW
REMOVE GRILLE
FIGURE5.
FRONTVIEW
OtiUOOL=::=JlOUUK~ :: —JIUDIO
ACCESS TO FAN SHAFT BEARINGS FOR OIL.
ING IS THROUGH LEFT FRONT ACCESS PANEL
OR BY REMOVING GRILLE
ROUTINE MAINTENANCE —
FILTERS —Units are shipped with throwaway filters in-
stalled (when flat type furnished). To insure troublefree
operation filters must be renewed or cleaned on a regular
basis. DO NOT NEGLECT! To service filter, open hinged ac-
cess door using 5/32” hex head wrench and place unit main
power On-Off switch in the Off position. See Figure 6.
FILTER CLIPJ
1HINGED ACCESS J
FILTER 000R
TYPES OF FILTERS —All types of filters should be check-
ed at least once amonth or more frequently in areas with
high dust or lint content.
1. Throwaway –(Glass fiber media in disposable cardboard
frame.) Replace as required.
2, Permanent —(Metal media with metal frame.) Immerse
and agitate in hot cleaning solution: 11/2pounds washing
soda to each 10 gallons of water. Drain and dry. Spray or
dip in filter oil and drain thoroughly.
3. Renewable —(Glass fiber media in metal frame.) Remove
filter pad from the frame and discard. Replace with glass
MODEL AH CEILING UNITS
throwaway media cut to the proper size.
4. Roll Filter —The filter indicator light will turn on automatic-
ally when filter media needs to be manually advanced.
Refer to separate roll filter installation and maintenance
instructions, part number GO-1009, for details. (Instructions
are attached to the inside of the right-hand end panel.)
When media in unit is exhausted, areplacement spool is
available which contains fifty feet of 14” wide media.
NOTE: Use of synthetic filter media is NOT RECOMMENDED.
IMPORTANT: AIR VENT OPENINGS IN THE FAN MOTOR
MUST BE KEPT CLEAR.
OILING —Use only high grade SAE 20 or 30 weight nondeter-
gent oil. Ball bearing type motors and fan shaft end bearing
(ball type) do not require oiling and there is no provision to
do so. Sleeve bearing motors should have three drops of oil
added once every year. DO NOT OVER OIL. See Figure 7.
for oil points. Sleeve type fan shaft end bearing should have
the bearing cup filled once every year. See Figure 8for oil
point. Access to the oiling point is gained by opening the bot-
tom access panel or by removing the left end panel for bear-
ing access and the right end panel for motor access using
5/32” hex head wrench
FIGURE7.
FAN MOTOR
OIL HERE
m
oAIR
‘+ FLOW
FIGURE8.
LEFT VIEW
SnyderGeneml 13600 Industrial Park Blvd., P.O. Box 1551, Minneapolis, MN 55440 [phone]