Panasonic MVA Series Air Handling Unit Mva18 24 30 36 42 48 60 Fbas6hbcp Installation Operation And Maintenance Manual

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INSTALLATION—SERVICE CLEARANCES 
						

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Install the unit so that it is level or pitches
slightly –(1/8 inch) – toward the condensate
drain connection.
Anchor the unit to the plenum or platform
through the bottom flange using 2ea #10 sheet
metal screws on each side (4 screws total).
Ceiling Suspension: Mount the unit in ceiling-
suspended horizontal orientation per suspen-
sion details (Figure 4). Unit is NOT intended
to be wall mounted. Consult a qualified struc-
tural engineer for special mounting considera-
tions.
Install the unit so that it pitches slightly –(1/8
inch) – toward the condensate drain connec-
tion.
Condensate Drain
Install a trapped condensate drain line at unit drain
connection. All MVA units have 3/4 in. FPT con-
densate main and auxiliary drain connections.
Provide adequate trap clearance (trap depth) be-
neath the unit as indicated in Fig. 3. Provide
freeze-up protection as required to insure reliable
condensate drainage. Freeze protection
measures are customer-supplied and installed.
Pipe to condensate drain using PVC or copper or
other suitable material. Pitch drain piping down-
ward at a minimum slope of 1/8 inch per foot.
Pipe auxiliary drain to “tell tale” drain location or
floor drain to clearly indicate when condensate
drain service is required. Alternately, use a field-
provided condensate overflow detection device in
the auxiliary drain connection to provide alarm or
other controls action when the drain pan fills to the
level of the auxiliary drain.
Placing Unit In Ductwork
1. Utilize flexible transitions on supply and return
connections to reduce noise and vibration trans-
mission to the structure.
INSTALLATION
WARNING
INSURE THAT THE UNIT IS ADE-
QUATELY SUPPORTED FROM
STRUCTURE TO PREVENT DAMAGE
OR INJURY CAUSED BY FALLING
EQUIPMENT! If uncertain about how
to connect to the structure, consult a
qualified structural engineer.
Fig. 3 — Condensate Drain
2. W hen the connecting return air duct is
smaller than the coil inlet opening, construct
the transition piece so that the vertical and
horizontal dimensions of the transition piece
do not increase more then one inch for eve-
ry seven inches of length of the transition
piece.
2. Provide at least three feet of straight
duct work preceding the unit inlet.
Duct Insulation and Vapor Proofing:
Properly select and install duct insulation as
required by the application.
All externally insulated duct work must have
an adequate vapor seal for summer opera-
tion. This is particularly important where the
duct is exposed to highly humid conditions
in such places as attics, vented crawl spac-
es, unconditioned basements, and utility
rooms. The vapor seal prevents condensa-
tion of moisture in the insulating material
and subsequent loss of its insulating value.
NOT TO SCALE
MAINTAIN THESE DIMENSIONS FOR ADEQUATE TRAPSEAL:A = 3.5” MINIMUMB = 2.0” MINIMUM
NOTES:1. CONDENSATE DRAIN PIPING RECOMMENDATIONS:A. MINIMUM 3/4” Φ PIPE SIZE B. COPPER OR PVC PIPE MATERIALC. USE DIELECTRIC UNION FOR DISSIMILAR METALS.D. INSULATE PER PROJECT SPECIFICATIONS.2. PAD OR PLENUM HEIGHT AS REQUIRED TO INSTALLTRAP AND CONDENSATE DRAIN PIPING.3. AVOID BLOCKING FILTER SERVICE ACCESS W HENINSTALLING CONDENSATE DRAIN PIPING. 
						

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Figure 4
CEILING SUSPENSION DETAILS 
						

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INSTALLATION
CAUTION
Direct-expansion coils are shipped pressurized
with dry nitrogen. Release pressure from the coil
through valves in protective caps before remov-
ing caps.
Do not leave piping open to the atmosphere un-
necessarily. Water and water vapor are detri-
mental to the refrigerant system. Until the piping
is complete, recap the system and charge with
nitrogen at the end of each workday. Clean all
piping connections before soldering joints.
Failure to follow these procedures could result in
personal injury or equipment damage.
Refrigerant Piping
Refrigerant Coils: Direct-expansion coils
have liquid and suction line connections
through the front of the cabinet.CAUTION:
Use proper care when brazing including use
of heat sink (wet cloth or other method) to pre-
vent damage to liquid line and suction line
components.
Size and install refrigerant lines in accordance
with the condensing unit manufacturer’s in-
structions. Provide insulation on the suction
line, to prevent condensation. Provide insula-
tion on the liquid line if unit to be used for heat
pump service or if otherwise required.
Electric Heater Accessory
The electric heater may be factory-installed or
field-installed. See Figures 5 through 8.
Removal Procedure:
To remove the electric heater,
1. Disconnect and lock out electrical power
from the unit. Remove heater access panel.
Disconnect power wires from the power
switch—DANGER! - MAKE SURE there is no
voltage on these wires before disconnecting!
2. Disconnect 2 harness connectors at the
blower deck.
3. Remove 2 screws holding heater support
feet to the blower deck.
4. Remove 4 screws that mount the heater to
the heater bulkhead. Handle heater carefully
to avoid damaging the wire heating elements.
Remove heater from the unit.
DANGER
WARNING:Hazardous voltage.Only qualified
personnel must install the electrical service. Dis-
connect and Lock Out all incoming power sources
before connecting to electrical service.
WARNING:This appliance must be permanently
grounded in accordance with the National Electrical
Code and local code requirements.
WARNING: For use with copper conductors only.
Fig. 5 — Heater Accessory Installed
(right side panel not shown)
Fig. 6 — Heater Accessory Installed
(right side and heater access panels
not shown)
System Design Regulation
When connecting MVA units in the VRF sys-
tem (mix or all),keep indoor/outdoor unit
capacity ratio with the range of 50% to
130%.For other conditions, refer to the VRF
System standard piping design regulations. 
						

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INSTALLATIONDANGER
WARNING:Hazardous voltage.Only qualified
personnel must install the electrical service. Dis-
connect and Lock Out all incoming power sources
before connecting to electrical service.
Install Procedure:
To install the electric heater,
1. Disconnect and lock out electrical power from
the unit. Remove heater access panel. Discon-
nect field power wires from the unit power wires.
DANGER! - MAKE SURE there is no voltage
supply to the unit before proceeding!
2. Disconnect and discard 1 harness connector at
the blower deck.
3. Remove blank plate from heater access panel
(covers square hole for breaker style power
switches).
4. Remove SAT sensor and sensor holder from
heater bulkhead and reposition on unit discharge
ductwork routing through auxiliary SAT sensor
hole on top panel.
5. Install SAT 3 feet after the first 90 degree turn
in the discharge ductwork.
6. Remove plate on the heater bulkhead (4
screws).
7. Install heater by carefully supporting the heater
and inserting it into the opening in the heater bulk-
head. NOTE: Make sure to guide the pin into the
hole at the back of the heater shroud. Secure the
heater to the bulkhead with 4 screws.
8. Connect 2 wiring harnesses (male) to the
Fig. 7 — Heater Accessory Removal
(right side and heater access panels
not shown for clarity)
matching female receptacles in the blower deck.
9. Connect field wiring to the breaker-style power
switches on the front of the heater.WARNING! Be
sure to provide the appropriate wire size and
branch circuit protection as required by the unit
nameplate!
10. Install the heater access panel.
11. Install the silicone cover “boot” over the top of
the power switches. This protects them from dust
buildup. The switches may be activated through the
flexible boot material.
12. Mark the nameplate label with the matching
heater kW rating. Label is located on the exterior of
the front top panel.
13. Update EEPROM settings to values shown in
the table. Refer to test run manual for detailed in-
Fig. 8 — Heater
Accessory
Installed
PIN
HEATERSHROUD
HEATERACCESSPANELCOVERBOOT
HEATERSHROUD
RIGHTSIDE
HEATERASSEMBLY
HEATERBULKHEAD
POWERSWITCH(ES)
Item Code New Settings
07 0001
38 0002
3C -001 
						

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Typical wiring diagrams are shown on the following
pages FOR REFERENCE. Always refer to the wir-
ing diagram on the air handling unit for actual wir-
ing.
NOTE: CHECK MOTOR RATING PLATE FOR
CORRECT LINE VOLTAGE.
Connect electrical service to unit. Refer to unit wir-
ing diagram.
Power Wiring
For power supply connection, route field power wir-
ing L1 and L2 and connect either:
1. Unit W ithout EH: to field-provided and installed
disconnect switch and from switch to power
entry (unit side) and to unit power leads inside
the unit electrical section; or
2. Unit W ith EH: into the unit through power entry
(unit side) and then to the factory installed pow-
er switch inside the electrical section (see Fig-
ure 9). Note: power switch looks like a circuit
breaker butdoes not provide overload pro-
tection. Power switch provided only with elec-
tric heater (field kit or factory installed). NOTE:
When electric heat greater than 10kW is pro-
vided, two power supply circuits are required,
as shown on the wiring diagram.
Refer to nameplate or Electrical Ratings (page 30)
for FLA, maximum overcurrent protection device
(MOPD) and minimum circuit ampacity (MCA). Also
refer to wiring diagram affixed to unit to make con-
trol and power wiring connections. For new heater
installation, mark the nameplate label with the
matching heater kW rating. Label is located on the
exterior of the front top panel.
NOTE: Installer is responsible for power wiring and
branch circuit over current protection.
Control Voltage Wiring
Control voltage wiring may enter the unit at the con-
trol box located behind the blower access door, or
DANGER
NEVER enter an enclosed fan cabinet or reach into
a unit while the fan is running.
LOCK OPEN AND TAG the fan motor power dis-
connect switch before working on a fan. Take fuses
with you and note removal on tag. Electric shock
can cause personal injury or death.
LOCK OPEN AND TAG the electric heat coil power
disconnect switch before working on or near heat-
ers.
Failure to follow these warnings could lead to per-
sonal injury or death.
DANGER
WARNING:Hazardous voltage.Only qualified
personnel must install the electrical service. Dis-
connect and Lock Out all incoming power sources
before connecting to electrical service.
WARNING:This appliance must be permanently
grounded in accordance with the National Electrical
Code and local code requirements.
WARNING: For use with copper conductors only.
INSTALLATION-ELECTRICAL
Figure 9
Unit with Electric Heat
CAUTION
Use only copper conductors for field-installed elec-
trical wiring. Unit terminals are not designed to
accept other types of conductors.
Do not allow wiring to touch the refrigerant tubing,
compressor, or any moving parts of the fan.
Make wiring connections in accordance with the
system wiring system diagram and these instruc-
tions. Wrong wiring may cause improper operation
or unit damage!
Unauthorized changes in the internal wiring can be
very dangerous. The manufacturer will accept no
responsibility for any damage or malfunction that
occurs as a result of such unauthorized changes.
other convenient location. Control voltage wiring
leads exit the bottom of the control box and are
ready for field-connection.
CAUTION!To prevent malfunction of the air condi-
tioner caused by electrical noise, route control wiring
and inter-unit control wiring SEPARATELY FROM
THE POWER WIRING!
POWERSWITCH 
						

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DANGER
WARNING:Hazardous voltage.Only qualified
personnel must install the electrical service. Dis-
connect and Lock Out all incoming power sources
before connecting to electrical service.
WARNING:This appliance must be permanently
grounded in accordance with the National Electrical
Code and local code requirements.
WARNING: For use with copper conductors only.
INSTALLATION-ELECTRICAL
General
Provide strain relief where field wiring passes
through cabinet. Wiring within the cabinet has
been positively located and supported so that it
does not pass over sharp metal edges or come in
contact with moving parts. After servicing, position
wiring properly in the original supports.
All field-installed wiring, including the electrical
ground, MUST comply with the National Electrical
Code (NEC) as well as applicable local codes. In
addition, all field wiring must conform to the Class
II temperature limitations described in the NEC.
Refer to factory wiring diagrams installed in the
unit. Use the MCA and MOPD from the nameplate
or electric heat nameplate or Electrical Ratings
(page 30) to size power supply wiring and overcur-
rent protection device. Installation must comply
with NEC and local codes.
For communicating controls, refer to Figures 10
through 13 for max lengths, sizing and intercon-
nections. Refer to the condensing unit opera-
tion manual for more details.
Figure 10
Building System Wiring Diagram
(multiple indoor & outdoor units)
( A ) In t e r- u n it ( b e t we e no u t d o o r a n d in d o o r u n it s )c o n t ro l wirin g
( B ) R e mo t e c o n t ro l wirin g
AWG #18 (0.7 5 mm2) AWG #18 (0 .7 5 mm2)
Ma x. 3 ,2 80 ft. Max. 1,6 40 ft.
( C ) C o n t ro l wirin g f o r g ro u pc o n t ro l( D ) In t e r- o u t d o o r u n itc o n t ro l wirin g
AWG #18 (0.7 5 mm2) AWG #18 (0 .7 5 mm2)
Ma x. 6 50 ft. (To ta l) Ma x. 9 80 ft.
Contr ol w ir ing
NOTE:See table below for wire requirementsfor lines above marked “A”, “B”, “C” and “D”.
CAUTION
Loose wiring may cause the terminal to overheat
or result in unit malfunction or cause a fire hazard.
Insure that all wiring is tightly connected! 
						

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INSTALLATION-ELECTRICAL
Figure 11
Inter-Unit Control Wiring
Do not install the inter-unit control wiring
in a way that forms a loop.
Figure 12
Inter-Unit Control Wiring
Do not install inter-unit control wiring with splic-
es or “star branch” pattern. Star branch wiring
causes misaddress setting errors.
If branching the inter-unit control wiring,
the number of branch points should be
16 or fewer. (Branches less than 3.3 ft.
are not included in the total branch num-
ber.)
Figure 13
Branched Inter-Unit Control Wiring 
						

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INSTALLATION-ELECTRICAL (cont’d)
TYPICAL WIRING DIAGRAM—
Unit sizes 18 & 24
TYPICAL WIRING—MVA18, MVA24 
						

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INSTALLATION-ELECTRICAL (cont’d)
TYPICAL WIRING DIAGRAM—
Unit sizes 30, 36, 42, 48 & 60
TYPICAL WIRING—MVA30, MVA36,
MVA42, MVA48, MVA60