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Enviro VDD, HDD Installation Operation & Maintenance

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DIRECT DRIVE BLOWER-COIL UNITS
INSTALLATION, OPERATION & MAINTENANCE
Model VDD
Form ET115.24-NOM12 (718)
Model HDD
TABLE OF CONTENTS
Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Safety Considerations ....................... 1
Section One - Receipt & Initial Installation
Direct Drive Blower-Coil Series Features......... 2
Preface ................................... 2
Unpacking & Inspection ...................... 3
Code Compliance...........................3
Handling and Installation ..................... 3
Unit Rigging and Placement...................4
Drain Pan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Coils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Cooling/Heating Medium Connections ........... 6
Ductwork Connections . . . . . . . . . . . . . . . . . . . . . . . 6
Electrical Connections ....................... 6
Electrical Enclosure ......................... 7
Condensate Drain and Traps . . . . . . . . . . . . . . . . . . 8
Service and Clearance Requirements ........... 9
Clearance ................................ 11
Section Two - Start-Up
General.................................. 12
Cooling/Heating System.....................12
Air System Balancing ....................... 12
Motor & Fan Data .......................... 13
Water System Balancing .................... 13
Controls Operation ......................... 13
Section Three - Normal Operation &
Periodic Maintenance
General.................................. 14
Motor/Blower Assembly ..................... 14
Coil .....................................15
Electric Resistance Heater Assembly........... 15
Electrical Wiring & Controls .................. 16
Filters, Throwaway ......................... 16
Drain....................................17
Optional Item Installation .................... 17
Condensate Float Switch Installation........ 17
Replacement Parts......................... 18
Section Four - Discrete Components
Fan Motor Control.......................... 19
Installation ............................... 19
Reference Wire Diagram .................... 20
Inputs and Outputs ......................... 21
Tools Needed for Installation/Troubleshooting .... 21
Jumpers ................................. 21
Checking Wire Harnesses ................... 22
Section Five - Troubleshooting
Discrete Components....................... 23
EC Motor ................................ 24
Cooling System ........................... 24
Electric Heat .............................. 25
ii
Section Six - Inspection &
Start-Up Checklist
Inspection & Start-up Checklist ............... 29
ENVIRO-TEC
SAFETY SYMBOLS
The following symbols are used in this document to alert the reader to areas of potential hazard:
DANGER indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.
WARNING indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
SAFETY CONSIDERATIONS
The equipment covered by this manual is designed for safe and reliable operation when installed and operated
within its design specication limits. To avoid personal
injury or damage to equipment or property while installing or operating this equipment, it is essential
that qualied, experienced personnel perform these functions using good judgment and safe practices. See the following cautionary statements.
ELECTRICAL SHOCK HAZARDS. All power must be disconnected prior to installation and servicing this equipment. More than one source of power may be present. Disconnect all power sources to avoid electrocution or shock injuries.
MOVING PARTS HAZARDS. Motor and Blower must be disconnected prior to opening access panels. Motors can start automatically, disconnect all power and control circuits prior to servicing to avoid serious crushing or dismemberment injuries.
HOT PARTS HAZARD. Electric Resistance heating elements must be disconnected prior to servicing. Electric Heaters may start automatically, disconnect all power and control circuits prior to servicing to avoid burns.
CAUTION identies a hazard which could lead to damage to the machine, damage to other equipment and/or environmental pollution. Usually an instruction will be given, together with a brief explanation.
NOTE is used to highlight additional information which may be helpful to you.
Check that the unit assembly and component weights can be safely supported by rigging and lifting equipment.
All assemblies must be adequately secured during lifting and rigging by temporary supports and restraints until equipment is permanently fastened and set in its nal location.
All unit temporary and permanent supports must be capable of safely supporting the equipment’s weight and any additional live or dead loads that may be encountered. All supports must be designed to meet applicable local codes and ordinances.
All fastening devices must be designed to mechanically lock the assembly in place without the capability of loosening or breaking away due to system operation and vibration.
Protect adjacent ammable materials when brazing. Use flame and heat protection barriers where needed. Have re extinguisher available and ready for immediate use.
ENVIRO-TEC
1
SECTION ONE - RECEIPT & INITIAL INSTALLATION
Direct drive fan and EC motor
1" duct collar allows for quick connection of duct work
Three different EC motor control options
Door interlocking disconnect
DIRECT DRIVE BLOWER-COIL FEATURES
Optional closed cell foam insulation
NEMA 1 control enclosure houses disconnect, fusing, and more
3, 4 or 6 row cooling coil with 1 or 2 row heating coil in preheat or reheat
Hanger holes in top and bottom panels for thru rod installation
Auxiliary drain pan connection
Access panels on both sides for easy access to blower and motor
PREFACE
ENVIRO-TEC direct drive blower-coils represent a prudent investment which can, with proper installation, operation, and regular maintenance, give trouble-free
operation and long service.
Your equipment is initially protected under the manufacturer’s standard warranty; however, this warranty is provided under the condition that the steps outlined in this manual for initial inspection, proper installation, regular periodic maintenance, and everyday
operation of the equipment be followed in detail. This
manual should be fully reviewed in advance of any
actual work being done on the equipment. Should any questions arise, please contact your local Sales Representative BEFORE proceeding.
The equipment covered by this manual is available with
a vast variety of options and accessories. Consult the
approved unit submittal, order acknowledgement, and other manuals for details on the options and accessories
provided with the equipment on each project.
No attempt should be made to handle, install, or service any unit without following safe practices regarding mechanical equipment.
All power must be disconnected before any installation or service should be attempted. More than one power source may be supplied to a unit. Power to remote mounted control devices may not be supplied through the unit. Never wear bulky or loose tting clothing when working on any mechanical equipment. Gloves should only be worn when required for proper protection from heat or other possible injury. Safety glasses or goggles should always be worn when drilling, cutting, or working with chemicals such as refrigerants or lubricants.
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ENVIRO-TEC
Never pressurize any equipment beyond specied operating pressures. Always pressure test with some inert uid or gas such as clear water or dry nitrogen to avoid possible damage or injury in the event of a leak or component failure during testing.
Always protect adjacent flammable material when welding, brazing or soldering. Use suitable heat shield material to contain sparks or drops of solder. Have re extinguisher available for use when welding or brazing.
The manufacturer assumes no responsibility for personal injury or property damage resulting from improper or unsafe practices during the handling, installation,
service, or operation of any equipment.
UNPACKING & INSPECTION
All units are carefully inspected at the factory throughout the manufacturing process under a strict detailed quality assurance program, and where possible, all major components and subassemblies are carefully tested for
proper operation and veried to be in full compliance with the factory manufacturing documents. Customer
furnished components such as control valves, switches
and DDC controls are not factory tested.
Each unit is carefully packaged for shipment to avoid
damage during normal transport and handling. The
equipment should always be stored in a dry place in the
proper orientation as marked on the carton.
All shipments are made F.O.B. factory and it is the
responsibility of the receiving party to inspect the
equipment upon arrival. Any obvious damage to the
carton and/or its contents should be recorded on the bill of
lading and a claim should be led with the freight carrier.
is led, the unit, shipping carton, and all packing must be retained for physical inspection by the freight carrier.
All equipment should be stored in the factory-shipping
carton with internal packing in place until installation.
At the time of receipt, the equipment type and arrangement should be verified against the order
documents. Should any discrepancy be found, the local Sales Representative should be notied immediately so that the proper action may be instituted. Should
any question arise concerning warranty repairs, the factory must be notified BEFORE any corrective
action is taken. Where local repairs or alterations can
be accomplished, the factory must be fully informed as
to the extent and expected cost of those repairs before work is begun. Where factory operations are required,
the factory must be contacted for authorization to return equipment and a Return Authorization Number will be
issued. Unauthorized return shipments of equipment
and shipments not marked with an authorization number
will be refused. In addition, the manufacturer will not accept any claims for unauthorized expenses.
CODE COMPLIANCE
This equipment has been manufactured and certied to conform to UL Standard for Heating and Cooling Equipment, UL 1995 (4th Edition) and to CSA Standard C22.2 No. 236. It bears the ETLc listed mark under Intertek Client #41629.
HANDLING AND INSTALLATION
While all equipment is designed for durability and
fabricated for sturdy construction and may present a rugged appearance, great care must be taken to assure that no force or pressure be applied to the coil, piping or
drain stub-outs during handling. Also, depending on the
options and accessories, some units could contain delicate
components that may be damaged by improper handling. Wherever possible, all units must be maintained in an
upright position and handled by the chassis as close as
possible to the mounting point locations.
After determining the condition of the carton exterior,
carefully remove each unit from the carton and inspect
for hidden damage. At this time check to make sure that “furnished only” items such as switches, thermostats, etc., are accounted for. Any hidden damage should be recorded
and immediately reported to the carrier and a claim
must be led. In the event a claim for shipping damage
ENVIRO-TEC
The equipment covered in this manual IS NOT suitable for outdoor installations. The equipment should never
be stored or installed where it may be subjected to a
hostile environment such as rain, snow, or extreme temperatures.
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During and after installation, special care must be taken to prevent foreign material such as paint, plaster, and drywall dust from being deposited in the drain pan, coil,
or on the motor or blower wheels. Failure to do so may
have serious adverse effects on unit operation and in the case of the motor and blower assembly, may result
in immediate or premature failure. All manufacturers’
warranties are void if foreign material is allowed to be
deposited on the motor or blower wheels of any unit. Some units and/or job conditions may require some form of temporary covering during construction.
While the manufacturer does not become involved
in the design and selection of support methods and components, it should be noted that unacceptable system operating characteristics and/or performance may result from improper or inadequate unit structural
support. In addition, adequate clearance must be
provided for service and removal of the equipment and
its accessory components. Anchoring the equipment in
place is accomplished by using the mounting points provided and positioning the unit to maintain the unit
on a LEVEL plane. The drain pan is internally sloped toward the outlet connection. Care must be taken to
insure that the unit drain pan does not slope away from
the outlet connection.
UNIT RIGGING AND PLACEMENT
Install ductwork to comply with ASHRAE Fundamentals Handbook, SMACNA, NFPA 90A and local code.
The installation must conform with local building codes
and the National Electric Code.
Locate unit support in accordance with the mechanical and structural plans. If so equipped, locate the isolator
placement and correct size as shown on the submittal
drawing.
Ceiling suspension of horizontal units have factory
provisions for thru bolt hanger rods. If oor mount
isolators are required for either horizontal or vertical
units, then factory or eld provisions must be made for isolator attachment. Vertical units can be mounted directly to the oor or on a base rail. For units with isolators but no base rail, 6" legs are required and will need to be mounted to the base of the unit. If a base rail
is provided, isolators can be installed in mounting holes
provided on this base rail.
Do not handle the unit using coil stubout connectors, as
damage may occur at brazed joint(s).
The unit’s drain pan is factory sloped toward the drain connection when the unit is installed level and plumb.
Figure 1a: Side view
Threaded rod
Unit
Figure 1b: Installation detail
Nut
Washer
Optional vibration isolator
4
Figure 1a-1b: Typical ceiling installation
ENVIRO-TEC
DRAIN PAN
Standard drain pans are constructed of single wall galvanized steel (with an option for stainless steel) and sit on insulation. The drain protrudes from the unit
cabinet and can be equipped with a secondary drain
connection. See illustration below.
COILS
All blower-coils are available in 2 or 4 pipe congurations. Heating coils are available in reheat or preheat position. Heating and cooling coils are available with right, left or opposite side connections.
Verify that the proper types of service are actually
provided to the unit. On units with steam heating coils, the maximum steam pressure applied to the unit should never exceed 15 PSIG. The drain piping and steam
trap should be sized and routed to allow for proper
condensate ow. The routing and sizing of all piping,
and the type and sizing of all wiring and other electrical components such as circuit breakers, disconnect
switches, etc., should be determined by the individual
job requirements and should not be based on the size
and/or type of connection provided on the equipment.
All installations should be made in compliance with all
governing codes and ordinances. Compliance with all codes is the responsibility of the installing contractor.
Figure 2a
Figure 2b
Figure 2a-2b: Drain pan access
ENVIRO-TEC
5
COOLING/HEATING MEDIUM CONNECTIONS
Toxic residues and loose particles resulting from manufacturing and eld piping techniques such as joint compounds, soldering ux, and metal shavings may be present in the unit and the piping system. Not for use with domestic or potable water systems.
Submittals and Product Catalogs detailing unit operation,
controls, and connections should be thoroughly reviewed BEFORE beginning the connection of the
various cooling and/or heating mediums to the unit.
All accessory valve packages are to be eld provided
and installed as required and all service valves should
be checked for proper operation. Refer to the valve component manufacturer’s IOM manual for proper installation, troubleshooting, and operational guidance.
All water coils must be protected from freezing after initial lling with water. Even if the system is drained, unit coils may still hold enough water to cause damage when exposed to temperatures below freezing.
Refrigerant systems should be tested with dry nitrogen rather than air to prevent the introduction of moisture
into the system. In the event that leaking or defective components are discovered, the Sales Representative must be notied BEFORE any repairs are attempted.
All leaks should be repaired before proceeding with
the installation.
DUCTWORK CONNECTIONS
All ductwork and/or supply and return grilles (provided by others) should be installed in accordance with the project plans and specications. If not included on the
unit or furnished from the factory, ENVIRO-TEC supply
and return grilles are available in a variety of types.
Units are congured from the factory with duct collars for attaching ductwork. The factory suggests using galvanized sheet metal ductwork or a exible canvas attached to the duct collars using sheet metal screws. Duct connections should follow SMACNA standards and national and local codes.
All units must be installed in non-combustible areas. Some models are designed to be connected to duct-work with a MINIMUM amount of external static pressure.
Consult the approved submittals and the product catalog
for unit external static pressure limitations.
Units provided with outside air for ventilation should
have some form of low temperature protection to
prevent coil freeze-up.
It should be noted that none of these methods would
adequately protect a coil in the event of power failure.
The safest method of freeze protection is to use glycol
in the proper percent solution for the coldest expected air temperature.
The manufacturer assumes no responsibility for undesirable system operation due to improper design, equipment or component selection, and/or installation of
ductwork, grilles, and other eld supplied components.
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ELECTRICAL CONNECTIONS
The unit nameplate lists the unit electrical characteristics such as the required supply voltage, fan and heater
amperage and required circuit ampacities. The unit-wiring diagram shows all unit and eld wiring connection points. Since each project is different and
each unit on a project may be different, the installer must be familiar with the wiring diagram and nameplate on
the unit BEFORE beginning any wiring. This unit is not acceptable for installation in hazardous/explosive areas.
ENVIRO-TEC
ELECTRICAL ENCLOSURE
Figure 3: Electrical enclosure
The electrical control enclosure provides access to
the electrical compartment. This compartment houses all electric heat and control components. Terminals
are furnished for simple power and control wiring
connections. Multiple knockouts allow wiring entries from either side of the compartment.
Any devices such as fan switches or thermostats
that have been furnished from the factory for eld
installation must be wired in strict accordance with the
applicable wiring diagrams. For electrical devices that are eld mounted and provided by others, please refer to the original manufacturer’s IOM for proper installation, troubleshooting and operation guidance. Failure to do so
could result in personal injury or damage to components
and will void all manufacturer’s warranties.
All eld wiring should be done in accordance with governing codes and ordinances. Any modication of
the unit wiring without factory authorization will result in voiding of all factory warranties and will nullify any
agency listings.
The manufacturer assumes no responsibility for any
damages and/or injuries resulting from improperly eld installed or wired components.
This unit is listed to UL/CSA standards. All modications
to line voltage wiring must be performed in accordance
with the NEC and inspected by ETL to maintain product listing. Unauthorized modication to any wiring may impact unit performance and void ETL listing and/or product warranty.
All components furnished for eld installation, by either
the factory or the controls contractor should be located
and checked for proper function and compatibility. All
internal components should be checked for shipping
damage. After installation and before energizing
the unit, verify voltage and check that all electrical
connections are tight. Electrical connections should be periodically checked for tightness.
ENVIRO-TEC
7
CONDENSATE DRAIN AND TRAPS
Trap detail for negative
cabinet static pressure
Trap detail for positive
cabinet static pressure
NO BASE RAIL
Housekeeping pad Required to accommodate trap height
WITH BASE RAIL
Depending on static
pressure, housekeeping pad may not be needed for trap installation
WITH BASE RAIL AND HOUSEKEEPING PAD
Drain lines should be at least the same size as the drain
pan connection. Properly sized traps should be used to
allow the condensate from the coils to drain from the
drain pan. See Fig. 4.
Figure 4: Condensate drain and traps
8
LD13929
ENVIRO-TEC
SERVICE AND CLEARANCE REQUIREMENTS – MODEL HDD
ENVIRO-TEC
9
SERVICE AND CLEARANCE REQUIREMENTS – MODEL VDD
10
ENVIRO-TEC
Clearance
All units, including those with electric heat, are listed
for zero clearance to combustibles.
Sufficient clearance for normal servicing of this equipment is recommended.
All electrical panels must have 36” working space in
front of panel to meet National Electric Code; however, local inspectors may wave this requirement if the hinged
cover has a 90° free swing.
FIELD WIRING
Prior to installing any wiring, check the unit name plate for main power voltage, control voltage, transformer sizing and any fuse sizing. All eld wiring must comply with National Electric Code and local code require-
ments.
Tighten all wiring lugs and terminals prior to connecting power to the unit, as they may loosen during
transportation.
Route the power lines to the power distribution
terminals inside the control enclosure. If a factory wired
disconnect switch is installed, then connect the power
lines to the line side of the switch.
Mount and wire any eld installed items as indicated on the factory supplied wiring diagram. When mounting eld installed components, do not jumper out or rewire
any factory wiring without written approval from
ENVIRO-TEC. Violation will void warranty.
TABLE 1: UNIT WEIGHT DATA (LBS./KG)
COMPONENT
BASE UNIT 115 [52] 133 [60] 152 [69] 175 [79] 287 [130] 305 [139] 357 [162] 375 [170]
MIXING BOX 46 [21] 54 [25] 65 [30] 90 [41] 105 [48] 105 [48] 162 [74] 162 [74]
BLOW THRU ELECTRIC
HEATER
1 ROW - DRY 12 [5] 14 [6] 17 [8] 21 [10] 26 [12] 26 [12] 32 [15] 32 [15]
1 ROW - WET 14 [6] 16 [7] 20 [9] 25 [11] 32 [15] 32 [15] 41 [19] 41 [19]
2 ROW - DRY 17 [8] 21 [10] 26 [12] 33 [15] 42 [19] 42 [19] 52 [24] 52 [24]
2 ROW - WET 21 [10] 26 [12] 32 [15] 42 [19] 54 [24] 54 [24] 69 [31] 69 [31]
COIL
ROWS
NOTES:
1. Unit weight data is shipping weight in pounds [kilograms].
3 ROW - DRY 23 [10] 28 [13] 35 [16] 45 [20] 57 [26] 57 [26] 72 [33] 72 [33]
3 ROW - WET 29 [13] 36 [16] 44 [20] 59 [27] 75 [34] 75 [34] 95 [43] 95 [43]
4 ROW - DRY 29 [13] 35 [16] 44 [20] 57 [26] 73 [33] 73 [33] 91 [41] 91 [41]
4 ROW - WET 37 [17] 45 [20] 56 [25] 74 [34] 96 [44] 96 [44] 121 [55] 121 [55]
6 ROW - DRY 40 [18] 49 [22] 62 [28] 81 [37] 104 [47] 104 [47] 132 [60] 132 [60]
6 ROW - WET 52 [24] 64 [29] 81 [37] 106 [48] 138 [63] 138 [63] 178 [81] 178 [81]
08 12 16 20
42 [19] 42 [19] 55 [25] 55 [25] 55 [25] 125 [57] 55 [25] 125 [57]
UNIT SIZE
30 (SINGLE
BLOWER)
40 (SINGLE
BLOWER)
30 (DUAL
BLOWER)
40 (DUAL
BLOWER)
ENVIRO-TEC
11
SECTION TWO - START-UP
GENERAL
Before beginning any start-up operation, the start­up personnel should familiarize themselves with the unit, options and accessories, and control sequence to
understand the proper system operation. All personnel
should have a good working knowledge of general start-up procedures and have the appropriate start-up
and balancing guides available for consultation.
The initial step in any startup operation should be a
nal visual inspection. All equipment, plenums, duct-
work, and piping should be inspected to verify that all systems are complete and properly installed and
mounted per ASHRAE and SMACNA guidelines, and
that no debris or foreign articles such as paper or drink
cans are left in the units or other areas. Each unit should
be checked for loose wires and hardware, free blower wheel operation, and loose or missing access panels or
doors. Except as required during start-up and balancing
operations, no blower-coil units should be operated without all the proper ductwork attached, supply and return grilles in place, and all access doors and
panels in place and secure. A clean lter of the proper size and type (as provided by factory or replacement matching the original factory size and type) must also be installed. Failure to do so could result in damage to
the equipment or building and furnishings, and/or void
all manufacturers’ warranties.
Blower-coils are not intended for temporary heat/cool
or ventilation. Units are not designed or equipped to operate in dusty construction environments. Operation
of the units in conditions outlined above could result in damage to the equipment or building and furnishings
and/or void all manufacturer’s warranties.
COOLING/HEATING SYSTEM
Prior to the water system start-up and balancing, the chilled/hot water systems should be ushed to clean
out dirt and debris, which may have collected in the
piping during construction. During this procedure, all unit service valves must be in the closed position. This
prevents foreign matter from entering the unit and/or
clogging the valves and metering devices. Strainers
should be installed in the piping mains to prevent this
material from entering the units during normal operation.
During system filling, air venting from the unit is accomplished by the use of the standard manual, or
optional automatic, air vent tting installed on the coil. In the case of the manual air vent tting, the screw should be turned counterclockwise no more than 1-½ turns to operate the air vent. Automatic air vents may
be unscrewed one turn counterclockwise to speed initial venting but should be screwed in for automatic
venting after start-up operations. Check to ensure that
no leaks are prevalent at the coils, coil connections,
piping packages, etc.
The air vent provided on the unit is not intended to replace the main system air vents and may not release air trapped in other parts of the system. Inspect the entire system for potential air traps and vent those areas as required, independently. In addition, some systems may require repeated venting over a period of time to properly eliminate air from the system.
AIR SYSTEM BALANCING
All duct-work must be complete and connected, and all
grilles, lters, access doors and panels must be properly
installed to establish actual system operating conditions
BEFORE beginning air balancing operations.
Each individual unit and attached duct-work is a unique
system with its own operating characteristics. For this
reason, air balancing is normally done by balance specialists who are familiar with all procedures required to properly establish air distribution and fan system
operating conditions. These procedures should not be attempted by unqualied personnel. Some selections may require air balancing in the eld.
After the proper system operation is established, the actual unit air delivery and the actual fan motor amperage draw for each unit should be recorded in a convenient place for future reference such as the inspection, installation, & start-up check sheet, a copy
of which is provided on the back of this manual. Contact the Sales Representative for additional copies of this sheet.
12
ENVIRO-TEC
TABLE 2: EC MOTORS
MAXIMUM MOTOR AMPERAGE
HORSEPOWER
115/1 208/1 230/1 277/1 208/3 230/3 480/3
1/2 7.7 5.0 5.0 4.1 2.0 2.0 1.0
1 12.8 9.4 9.4 6.9 3.7 3.7 1.7
3
1-1/2
3
2
3
3
NOTES:
1. Actual motor nameplate AMPs may vary, but will not exceed values shown.
2. Consult factory for applications requiring special motors.
3. Amp values are total amp values for (2) motors.
– – – – 4.4 4.4 2.2
25.6 18.8 18.8 13.8 7.4 7.4 3.4
-- -- -- -- 8.8 8.8 4.4
VOLTAGE/PHASE
WATER SYSTEM BALANCING
A complete knowledge of the hydronic system, its components, and controls is essential to proper water system balancing and this procedure should not be
attempted by unqualied personnel. The system must
be complete and all components must be in operating condition BEFORE beginning water system balancing
operations.
Each hydronic system has different operating characteristics depending on the devices and controls
in the system. The actual balancing technique may vary from one system to another.
After the proper system operation is established, the appropriate system operating conditions such as various
water temperatures and ow rates should be recorded in a convenient place for future reference.
Before and during water system balancing, conditions
may exist which can result in noticeable water noise
or undesired valve operation due to incorrect system
pressures. After the entire system is balanced, these conditions will not exist on properly designed and balanced systems.
CONTROLS OPERATION
Before proper control operation can be veried all other systems must be in proper operation. The correct water
and air temperatures must be present for the control
function being tested. Some controls and features are designed to not operate under certain conditions.
A wide range of controls and electrical options and accessories may be used with the equipment covered
in this manual. Consult the approved unit submittals,
order acknowledgement, and other manuals for detailed information regarding each individual unit and its
controls. Since controls and features may vary from
one unit to another, care should be taken to identify the controls to be used on each unit and their proper control sequence information provided by component manufacturers such as submittals and installation, operation, and maintenance manuals of their individual
controls is available upon request.
ENVIRO-TEC
13
SECTION THREE - NORMAL OPERATION & PERIODIC MAINTENANCE
GENERAL
Each unit on a job will have its own unique operating environment and conditions that may dictate a maintenance schedule for that unit that is different
from other equipment on the job. A formal schedule of
regular maintenance and an individual unit log should
be established and maintained. This will help to achieve the maximum performance and service life of each unit on the job.
Information regarding safety precautions contained in the preface at the beginning of this manual should be followed during any service and maintenance operations.
For more detailed information concerning service
operations, consult your Sales Representative.
MOTOR/BLOWER ASSEMBLY
The type of fan operation is determined by the control components and their method of wiring and may vary
from unit to unit. Refer to the wiring diagram for each unit for that unit’s individual operating characteristics.
The direct drive blower coil fan’s EC motors are permanently lubricated and do not require field
lubrication. Check periodically that all motor hardware is properly fastened and clear of all dirt and dust.
Should the assembly require extensive service, the
motor/blower assembly may be removed from the unit to facilitate such operations as motor or blower wheel/
housing replacement, etc. Dirt and dust should not be allowed to accumulate on the blower wheel or housing.
This can result in an unbalanced blower wheel condition
that can damage a blower wheel or motor. The wheel and
housing may be cleaned periodically using a vacuum cleaner and a brush taking care not to dislodge the
factory balancing weights on the blower wheel blades.
Figure 5a
Figure 5b
Figure 5a-5b: Motor access
14
ENVIRO-TEC
COIL
The entering air side of the coil may be cleaned in place
by removing the lters from the unit, accessing from the inlet, and then brushing the coil face between ns with a soft brush parallel to ns. To clean the leaving
air side of the coil, gain entry through the access door
and then follow the same brushing procedure. Do not brush perpendicular to n orientation as damage may occur. Brushing should be followed by cleaning with a vacuum cleaner. If a compressed air source is available,
the coil may also be cleaned by blowing air through the
coil ns from the leaving air face. Vacuuming should again follow this. Units provided with proper type of air lters, replaced regularly, may require periodic coil cleaning.
ELECTRIC RESISTANCE HEATER ASSEMBLY
Electric resistance heaters typically require no normal
periodic maintenance when unit air lters are changed properly. Other conditions and equipment may affect the operation and service life in the system. The two most
important operating conditions for an electric heater are
proper airow and proper supply voltage. High supply voltage and/or poorly distributed or insufcient airow over the element will result in element overheating. This
condition may result in the heater cycling on the high
limit thermal cutout. Open wire type heaters provided
have an automatic reset switch with a back-up high
limit thermal switch. Automatic reset switches are as
the name implies; they reset automatically after the
heater has cooled down. The high limit thermal cutout device is a manual reset safety device. With proper
unit application and during normal operation, the high
limit thermal cutout will not operate. This device only operates when some problem exists. ANY condition that causes high limit cutout MUST be corrected immediately. Once the high limit trips, it may be reset once the unit has cooled down. Refer to troubleshooting section for high limit reset instructions. High supply voltage also causes excessive amperage draw and may
result in tripping of the circuit breaker or blowing of
the fuses on the incoming power supply.
ENVIRO-TEC
Figure 6a
Figure 6b
Figure 6a-6b: Electric heater assembly
15
ELECTRICAL WIRING & CONTROLS
The electrical operation of each unit is determined by the components and wiring of the unit and may vary
from unit to unit. Consult the wiring diagram for the
actual type and number of controls provided on each
unit. The integrity of all electrical connections should be veried at least twice during the rst year of operation.
Afterwards, all controls should be inspected regularly
for proper operation. Some components may experience erratic operation or failure due to age. Wall thermostats
may also become clogged with dust and lint and should be periodically inspected and cleaned to provide reliable
operation. Please refer to controls manufacturer’s IOM for periodic maintenance instructions.
When replacing any components such as fuses, contactors, or relays, use only the exact type, size, and voltage component as furnished from the factory. Any
deviation without factory authorization could result in personnel injury or damage to the unit and will void all
factory warranties and listings. All repair work should
be done in such a manner as to maintain the equipment in compliance with governing codes and ordinances or
testing agency listings.
Figure 7a
More specific information regarding the use and
operating characteristics of the standard controls offered
by this manufacturer is contained in other manuals.
FILTERS, THROWAWAY
The type of throwaway lter most commonly used on blower-coil units should be replaced on a regular basis.
The time interval between each replacement should be
established based on regular inspection of the lter and should be recorded in the log for each unit. Refer to the chart below for recommended lter size for each product type and size. If the replacement lters are not purchased from the factory, the lters used should be the same type
and size as that furnished from or recommended by the
factory. Consult the factory for applications using lter types other than the factory standard or optional product.
TABLE 3: FACE AREA, FREE AREA & FILTER SIZES
UNIT SIZE
COIL FACE AREA
08 2.1 [0.20]
12 2.7 [0.25]
16 3.5 [0.33]
20 4.9 [0.46]
30 6.5 [0.60]
40 8.4 [0.78]
2" FLAT FILTERS
(QUANTITY) & SIZE
(1) 15.75 x 19.75 x 2
[400 x 502 x 51]
(1) 15.75 x 24.75 x 2
[400 x 629 x 51]
(2) 15.75 x 19.75 x 2
[400 x 502 x 51] (1) 15.75 x 19.75 x 2 [400 x 502 x 51] (1) 15.75 x 24.75 x 2 [400 x 629 x 51] (2) 24.75 x 15.75 x 2 [629 x 400 x 51] (1) 24.75 x 19.75 x 2 [629 x 502 x 51]
(3) 24.75 x 19.75 x 2
[629 x 502 x 51]
FILTER
FACE AREA
2.2 [0.20]
2.7 [0.25]
4.3 [0.40]
4.9 [0.46]
8.8 [0.82]
10.2 [0.95]
Figure 7b
Figure 7a-7b: Filter removal
NOTES:
1. Standard lters are 2" throwaway.
2. Filter sizes are nominal and standard size, measure in inches [millimeters].
3. Coil and lter face areas are measured in square feet [square meters].
4. Cooling and heating coils have same face area.
16
ENVIRO-TEC
DRAIN
The drain should be checked before initial start-up and at the beginning of each cooling season to assure that
the lines are clear. If it is clogged, steps should be taken to clear the debris so that condensate will ow easily. Periodic checks of the drain should be made during the cooling season to maintain a free owing condensate.
CONDENSATE FLOAT SWITCH INSTALLATION
Ensure oat switch assembly is rmly secured to the bracket. Ensure top of oat is below rim of pan. Switch
will trip when the water level reaches a point even
with top of oat when oat is in the down position. Sensitivity may be adjusted by threading switch assembly downward out of bracket if necessary.
Test switch by lifting oat with unit on. Unit should stop running if switch is correctly wired. Test switch sensitivity by lling pan and conrm switch stops unit before pan overows.
Should the growth of algae and/or bacteria be a
concern, consult an air conditioning and refrigeration supply organization familiar with local conditions for
chemicals available to control these agents. If cleaners
are used, they should be compatible with the materials
of construction for the coil and drain pan.
Supplier’s install instructions
1. Disconnect power to unit at main panel.
2. Clip switch bracket onto side of pan at low end and press rmly into place ensuring switch wires are positioned up ensure oat moves freely.
3. Secure bracket into side of pan using self-tapping sheet metal screw through upper hole in bracket.
4. Ensure oat switch assembly is rmly secured to bracket. Ensure top of oat is below rim of pan. Switch will trip when water level reaches a point even with top of oat (when oat is in down position). Sensitivity may be adjusted by
threading switch assembly downward out of
bracket if necessary.
5. Ensure wiring matches the wiring diagram provided with the unit.
6. Test switch by lifting oat with unit on. Unit should stop running if switch is correctly wired.
7. Test switch sensitivity. Fill pan and conrm that switch stops unit before pan overows.
8. Follow all Lock-Out Tag-Out procedures when performing condensate oat switch maintenance.
Figure 8a: Drain pan oat switch installed
Figure 8b: Drain pan oat switch diagram
ENVIRO-TEC
17
REPLACEMENT PARTS
Factory replacement parts should be used where possible to maintain the unit performance and
operating characteristics and the testing agency listings.
Replacement parts may be purchased through the local
Sales Representative.
Contact the local Sales Representative before attempting any unit modications. Any modications not authorized
by the factory could result in personnel injury and damage to the unit and could void all factory warranties
and regulatory listings.
When ordering parts, the following information must be supplied to ensure proper part identication:
1. Complete unit model number
2. Unit hand connection (right or left hand) while facing the direction of airow at the inlet
3. Complete part description including any numbers.
On warranty replacements, in addition to the information previously listed, the project CO # that appears on
the unit nameplate, is required. Contact local Sales Representative and refer to warranty policy.
All equipment and components sold through the Parts
Department are warranted under the same conditions as
the standard manufacturer’s warranty with the exception that the warranty period is 12 months.
18
ENVIRO-TEC
SECTION FOUR - DISCRETE COMPONENTS
FAN MOTOR CONTROL
Unit control with discrete components consists of a
transformer, fan enable relay and terminal strip for
customer and peripheral connections. The transformer
will vary in primary voltage depending on each unit’s
ordered options. The transformer will always have a 24VAC secondary voltage. An optional Hand-Off-Auto
switch may be used to provide manual and automatic
control of the fan.
A PWM board will provide the motor control signal to the motor. Refer to EC Motor Solo, Select and Sync
PWM IOM, All Products for more information about
the PWM and EC motors.
Peripheral devices (e.g., thermostat controllers, electric
heat relays, water valve actuators, condensate drain pan
oat switches, air dampers) are connected by either the OEM or by the installer at the terminal strip.
INSTALLATION
MOUNTING
Important: Do not overtighten the screws. Overtightening may strip the threads and will void the warranty.
Using #8 screws, install the components using the provided mounting holes for each component.
Risk of Electric Shock Disconnect or isolate all power supplies before making electrical connections. More than one disconnection or isolation may be required to completely de-energize equipment. Contact with components carrying hazardous voltage can cause electric shock and may result in severe personal injury or death.
WIRING
Install the wiring so it does not cause a hazard, and is
protected against electrical and mechanical damage.
Risk of electric shock Ground the transformer according to local, national, and regional regulations. Failure to ground the transformer may result in electric shock and severe personal injury or death.
The COM terminal on the secondary side of the transformer must be grounded per NEC requirements.
ENVIRO-TEC
19
ECR/SQ/TRANSMITTAL NO.
REVISION DESCRIPTION
INITIAL RELEASE
WIRING DIAGRAM
FOR REFERENCE
REFERENCE WIRE DIAGRAM
REV
1
88-90141
DRAWING NO.SHEETSCALE
1
1 00
OF
-01 1
UNCONTROLLED DOCUMENT WHEN PRINTED
PLEASE CHECK TO MAKE SURE DRAWING IS CURRENT.
THIS DRAWING MAY NOT REFLECT THE MOST CURRENT REVISION.
±3°
±0.063
±0.063
±0.063
±0.125
2
ANGULAR
SQUARE
CUT LENGTH
LENGTH
FORMED LENGTH
WELDING:
Cu TUBING:
STANDARD APPLIED TOLERANCES
DISC,1M
WD,3PH,DDBC,SOLO,1STG
PART NO.
TITLE MATERIAL
±5°
±1°
±3°
±0.031
±0.031
±0.031
±0.005
±0.016
CUT SIZE
CUT ANGLE
CUT SQUARE
FORMED ANGLE
HOLE DIA
FORMED DIM
FORMED ANGLE
FORMED SQUARE
OTHERWISE NOTED
DIMENSIONS ARE IN INCHES UNLESS
SHEET METAL:
DO NOT SCALE DRAWING
2
3
INCOMING
4
L3
POWER
L1 L2
DATECHECKED BYDATEDRAWN BY
ZONE
3
4
EC3255 SJR 05/18/18 MSS 05/18/18 NTS 88-90141
D D
C C
B B
A A
20
ENVIRO-TEC
INPUTS AND OUTPUTS
TABLE F.1 – TERMINAL STRIP IDENTIFICATION
Pin Signal Signal Name Description
Common side of transformer. Jumped to C (common) through JP1. If
1
S1 Common
application calls for oat switch JP1 is re-moved and oat switch is connected between S1 and C.
2
S2
3
R
4
C
5
C
6
Y Cool Chilled water valve actuator control input, and thermostat cooling output.
7
W Heat
8
G Fan Enable Used to allow external start-stop control from an external source.
TOOLS NEEDED FOR INSTALLATION/TROUBLESHOOTING
24VAC
Common
Transformer secondary “hot” connection (24VAC). In most cases, these terminals are internally connected on the terminal strip.
Low voltage common. These terminals are internally connected on the terminal strip.
Wire connection point for hot water valve actuator or 1st stage EH control input, and thermostat heating output.
• Digital multimeter capable of measuring 30 volts AC
• Screwdriver
• Fuse puller (optional)
TABLE F.2 – FIELD INSTALLED COMPONENT DESCRIPTIONS
Name Description
To install a oat switch, wire the oat switch leads into S1 and C on the screw terminals. After wiring the oat switch, remove jumper JP1. The JP1
Field-provided Float Switch
jumper must be removed for the oat switch to operate correctly.
Note: If a oat switch was installed in the factory, the oat switch may be
connected through a factory-provided harnesses.
To start or stop the fan from an external controller, wire the leads for the switch
Start/Stop for the fan
contacts that will be made or broken to R and G on the screw terminals. After wiring the switch, verify no jumper is installed between R and G.
Remote 3-speed switch (Requires SELECT pwm board)
JUMPERS
To add a remote 3-speed switch, remove the jumper between 24VAC and SPD3. Then wire the leads for the switch to 24VAC, SPD3 (High), SPD2 (Med) and SPD1 (Low) on the Select PWM board.
TABLE F.3 – JUMPER DESCRIPTION
Jumper Name Description
JP1
Float Switch Jumper
This jumper is installed between S1 and C when a oat switch is not installed. The jumper is removed when a oat switch is installed.
ENVIRO-TEC
21
CHECKING WIRE HARNESSES
To check three phase EC motor harness:
• Remove power from unit.
• Refer to wiring diagram.
• Unplug 12 pin wire harness connector from motor.
Note: 1.5HP and larger motors have separate motor controller. In this case, disconnect the 12 pin wire harness from motor controller.
• Disconnect the black, red, and blue harness wires
from the terminal strip in the electrical enclosure.
• Unplug the PWM wire harness from the motor harness.
• Verify continuity of wires on motor harness per
detail ‘A’ on wire diagram, then reconnect.
To check single phase EC motor power harness:
• Remove power from unit.
• Refer to wiring diagram.
• Unplug 5 pin motor power wire harness connector from motor.
• Disconnect motor power harness wires from the
lever nuts in the electrical enclosure.
• Verify continuity of wires, then reconnect.
To check EC motor PWM harness:
• Remove power from unit.
• Refer to wiring diagram.
• Unplug PWM wire harness from motor (single phase units) or from motor harness (three phase units).
• Unplug PWM wire harness from PWM board.
• Verify continuity of wires, then reconnect.
To check electric heat harness (dual blower units with electric heat):
Note: electric heat wire harness connects far side (second blower) heater to near side electrical enclosure.
• Remove power from unit.
• Refer to wiring diagram.
• Unplug electric heat wire harness at electrical enclosure.
• Verify resistance across pin 1 and pin 2 of wire harness. Near zero resistance indicates a shorted far side heater. Near innity resistance indicates a far side heater open circuit. Reconnect.
To check motor harness:
• Refer to wiring diagram.
• Remove power from the unit. Unplug motor harness 12 pin connector at motor or motor controller..
• Unplug motor harness from motor connetion or PWM board (depending on type of motor).Verify continuity of wires, then reconnect.
To check low voltage wire harnesses:
• Remove power from the unit. Unplug low voltage harness J1 connector and disconnect connections at other end of J1 harness.
• Use ohmmeter to check continuity for each conductor, then reconnect harness to J1 connector and to other connections.
Before reconnecting power to unit, verify all harnesses
are connected per diagram.
22
Use caution when inserting meter probe into plug. Excess force will damage contacts.
ENVIRO-TEC
Risk of Electric Shock Disconnect or isolate all power supplies before making electrical connections. More than one disconnection or isolation may be required to completely de-energize equipment. Contact with components carrying hazardous voltage can cause electric shock and may result in severe personal injury or death.
No routine maintenance is required for the discrete components.
TABLE F.4 – FAN MOTOR CONTROL
Jumper Name Description
No jumper between R
No 24VAC power
Fan motor will not run
Electric heat signal is not provided to contactor
and G without external
start/stop control installed
JP1 removed without oat switch or low
temperature sensor installed
Float switch or low temperature sensor tripped
Incorrect incoming line voltage
Damaged transformer
Improper wiring connections
No 24VAC power See above.
Hand-Off-Auto (HOA)
switch is set to Off
Fan speed is not commanded
Fan speed is not commanded
Verify that either an external start/stop or jumper between R and G is installed. If neither, install one of them.
Verify that either a oat switch, low temperature sensor or JP1 are installed. If none, install one of them.
Verify oat switch and/or low temperature sensor (if present) are made.
Verify incoming voltage to the unit per unit nameplate. Supply voltage must be within +/- 5% of unit nameplate..
Verify the secondary transformer voltage between R and S1 is 24VAC ± 10%. If not, verify primary transformer voltage is within tolerance. If the primary
voltage is within tolerance and the secondary voltage is not, replace the
transformer.
Verify that the unit is wired per the unit wiring diagram for incoming voltage. If the unit includes main fusing, verify that the fuses are not blown. Verify wire harness connections are secure. See “Checking Wire Harnesses” section.
Verify the HOA switch is not set to OFF.
Verify a fan enable is commanded from either jumper be-tween R and G, a unit-mounted or remote-mounted three speed switch, or a thermostat.
Verify that fan motor is running. A fan speed must be commanded to allow the electric heat contactor to energize on a call for heat.
ENVIRO-TEC
23
SECTION FIVE - TROUBLESHOOTING
EC MOTOR TROUBLESHOOTING GUIDELINES
For EC Motor troubleshooting questions please refer to the “EC Motor Solo, Select, and Sync PWM IOM, All Products” document found under the IOM Literature section of www.enviro-tec.com..
COOLING SYSTEM TROUBLESHOOTING GUIDELINES
Problem Possible cause Corrective action
Insufcient airow Verify proper airow.
Dirty water coil Check cleanliness of water coil. Clean as needed.
Verify operation of drain pan float switch, if present.
Insufcient
cooling
Unit sweats
Drain pan oat switch fault
Cooling valve not operating properly
Insufcient ow Verify liquid ow per system design.
Obstructed coil
[DX coils] Improper refrigerant charge
[DX coils] Insufcient cooling
liquid to coil
No call for cooling
Air leak in ducts/unit Verify integrity of unit. Verify ducts are properly sealed.
Pipe insulation Verify pipes are properly insulated
Damaged insulation Verify insulation at point of sweating
Unconditioned air to unit Verify conditioned air to unit
Drain pan is clogged Locate and remove blockage.
Disconnect switch and use volt-ohm meter to verify
continuity of switch and of wiring. Replace switch if faulty.
Verify cooling valve opens with call for cooling. Verify all manual valves are open.
Verify coil is unobstructed. Verify all manual valves are open and have liquid ow through system.
Charge to proper cooling.
Verify coolant ow in coil. Verify proper ow per system design.
Verify cooling signal at 'Y' terminals. Verify thermostat setting/operation.
24
ENVIRO-TEC
ELECTRIC HEATER TROUBLESHOOTING GUIDELINES
Problem Possible cause Corrective action
Verify that airow is sufcient to provide a minimum of
Insufcient airow
70 CFM per kW of electric heat. Heater is not designed to operate below 70 CFM/kW.
Verify that heat command signal is not dropping out. Re-view schematic. For standard heaters, verify 24VAC
Loss of demand
at heater control ‘W’ terminal. For multi-stage units, verify demand at W and S2 terminals. For units with proportional heater control, verify analog signal at COM and SIG terminals of Heat controller.
Loss of 24VAC Verify 24V at transformer and at ‘R’ terminal.
Electric heat will not operate unless fan motor is enabled. Possible loose wiring. Verify integrity of wiring to TS1 terminal. Possible loss of fan command. Verify fan relay
No airow
is enabled - 24VAC at coil of fan relay. Possible bad fan relay. If fan relay is enabled but doesn't actuate, replace relay. Possible Hand-Off-Auto switch fault (if present).
Electric Heat will not operate
CAUTION: UNIT MAY BE EXTREMELY HOT. TAKE GREAT CARE WHILE TROUBLE­SHOOTING
Primary limit switch tripped
If Hand-Off-Auto switch is in Hand position and 24VAC doesn't pass to fan relay, replace HOA switch.
Verify no loss of demand to unit. Verify that voltage exists on magnetic heater contactor during demand for heat. If demand reaches unit but not contactor, primary limit is tripped. It is an automatic reset limit switch that guards against overheating as a resulting of insufcient air passing over the limit switch. The primary limit switch(es) will auto-reset once the unit cools down. This may take up to an hour. NOTE: dual blower units have two heater racks and two primary limits.
Remove power from unit. Wait for unit to cool down. Disconnect primary limit wire or wire harness (refer to
Primary limit faulted or damaged
wire/wire harness
wire diagram for unit.) Verify continuity across primary limit. If primary limit is veried good, verify continuity across wire or harness and to each side of primary limit. If no continuity, replace wires or wire harness.
Secondary (high) limit switch
tripped
The secondary limit may be manually reset. If unit is hot, wait for the heater to cool down. This may take up to an hour. Reset switch(es). Verify if heater will start.
Improper wiring connections Verify wiring per wire diagram.
With power removed, inspect the heating elements, disconnect heater wire harnesses. (The harnesses with the
Open or damaged heater elements
black plug.) Use a volto-ohm meter to measure resistance
across the electric heat power harness coming out of the
heater section. If the meter measures an open or shorted circuit, replace with new elements.
ENVIRO-TEC
25
Problem Possible cause Corrective action
Damaged electric heat wire harness
With power removed, disconnect heater wire harnesses. Use a volt-ohm meter to verify continuity of electric heat power harness wires in the control enclosure section.
Remove power from unit. Wait for unit to completely
Secondary (high) Limit switch
fault
cool down. This may take up to an hour. Remove secondary limit switch from circuit. Verify continuity across (cooled) switch terminals. Replace switch if no continuity.
Verify heating demand voltage is at magnetic electric
heat contactor control coil terminals. If power is present
[Magnetic contactor] Electric
heat contactor fault
but contactor is not actuated, replace contactor. To verify
contactor: with power removed, unwire contactor and
verify continuity across contacts when manually operated.
Cover of contactor may need to be removed to access
manual operator. Replace contactor if faulty.
Electric Heat will not operate (cont.)
Contactor chattering
Possible insufcient airow. Verify unit develops mini­mum required CFM. Possible turbulent airow. Verify ductwork complies with ASHRAE Fundamentals Hand­book, SMACNA, NFPA 90A and local code. Possible undersized transformer. Verify 24V AC voltage.
Verify 24V AC control voltage is at magnetic electric heat
[Solid state relay] electric heat
safety contactor fault
safety contactor control coil terminals. If power is present at coil but contactor is not actuated, replace contactor. If power is not present at coil, verify primary limit switch.
[On/Off Solid state relay] Solid State Relay fault
[Solid state relay with proportional control] Heat
controller fault
Verify heating demand (24VAC control voltage) is at solid state relay control terminals. If power is present but relay is not actuated, replace relay.
Verify analog DC control signal is present at controller
SIG and COM input terminals. Verify that output control
voltage to solid state relay varies with variation in analog
input. Replace controller if not.
If proportional heat controller not faulted, verify solid
[Solid state relay with proportional control] Solid State Relay fault
state relay has DC control voltage at relay terminals. If
control voltage at terminals and relay fails to pass voltage
from safety contactor to heater, solid state relay is faulted. Replace relay.
26
ENVIRO-TEC
Problem Possible cause Corrective action
Verify that heat command signal is not dropping out. Review schematic. For standard heaters, verify 24VAC at
Loss of demand
heater control ‘W’ terminal. For multi-stage units, verify demand at W and S2 terminal. For units with proportional heater control, verify analog signal at COM and SIG terminals of Heat controller.
Heater will not operate if fan is not enabled. Verify
Loss of fan speed command
24VAC at fan relay coil and contact with EH command wire.
Unit must have sufcient airow to allow airow switch
Insufcient airow
to make. Verify airow switch is enabled: there should be 24VAC present at each side of switch while fan is running.
Electric Heat shuts down unexpectedly
Primary limit switch tripped
24VAC on EH signal wire but not at airow switch signies primary limit has tripped. The primary limit switch(es) will auto-reset once the unit cools down. This may take up to an hour. If limit trips again, verify heater is not overheating. NOTE: dual blower units have two primary limits.
The secondary limit may be manually reset. If unit is hot,
Secondary (high) limit switch
tripped
wait for the heater to cool down. This may take up to an hour. Reset switch(es). If limits trip again, verify heater is not overheating. NOTE: dual motor units have two heater racks.
Verify operation of any control device such as drain pan
Intermittent control device
oat switch, freeze stat, etc. When in doubt, jumper out and verify fan operation.
Loose wiring
Remove power from unit. Verify and/or tighten all wiring connections.
ENVIRO-TEC
27
Problem Possible cause Corrective action
Verify that airow is sufcient to provide a minimum of
Insufcient airow
70 CFM per kW of electric heat. Heater is not designed to operate below 70 CFM/kW.
Electric heater is overheating
CAUTION: UNIT MAY BE EXTREMELY HOT. TAKE GREAT CARE WHILE TROUBLE­SHOOTING
Improper duct connections
Obstructed ductwork
Intermittent fan
Incorrect voltage applied. Verify proper voltage to unit per unit label.
Improper wiring connections
Damaged heater elements
Safety magnetic heater contactor
short
Solid State heater relay (SSR)
short
Electric heaters require even airow across the face of the heater in order to operate properly. Verify ductwork is in­stalled per SMACNA and ASHRAE guidelines.
Verify no obstructions. Verify all dampers are full open while fan operates.
Verify fan motor runs continuously, providing even airow.
Verify wiring to schematic. Verify all jumpers installed on terminal strip per schematic.
Remove power from unit. Access the heater compartment. Verify heating elements are undamaged.
Remove heater command signal. Verify loss of 24VAC at heater contactor. If electric heat continues to operate and all wiring has been veried, replace contactor.
Remove heater command signal. Verify loss of 24VAC at SSR. If electric heat continues to operate and all wiring has been veried, replace contactor.
Review schematic. For standard heaters, there needs
to be continuous 24VAC at heater control 'W' terminal Intermittent demand for heating. Heater short cycling.
during demand for heat. For multi-stage units, verify
continuous demand signal at W and S2 terminal. For units
with proportional heater control, verify continuous analog
signal at SSR COM and SIG terminals.
Remove power. Access heater compartment to inspect
Open or damaged heater elements
heater coils. Note that dual motor units have two separate
heater racks.
Insufcient
heating
INSUFFICIENT HEATING CAUTION: UNIT MAY BE EXTREMELY HOT. TAKE GREAT CARE WHILE TROUBLE­SHOOTING
Loss of stage
Incorrect voltage applied Verify proper voltage to unit per unit label.
Electric heat contactor fault
Loss of demand for second stage. Verify 24VAC at coil
for stage 2 contactor.
Verify 24VAC at coil terminal for each electric heat
contactor. If power is present but contactor is not actuated,
replace contactor. To verify contactor: with power
removed, unwire contactor and verify continuity across
contacts when manually operated. Cover of contactor may
need to be removed to access manual operator. Replace
contactor if faulty.
Possible insufcient airow. Verify unit develops
minimum required CFM. Possible turbulent airow.
Contactor chattering
Verify ductwork complies with ASHRAE Fundamentals
Handbook, SMACNA, NFPA 90A and local code.
Possible under sized transformer. Verify 24VAC voltage.
24VAC on EH signal wire but not at airow switch
signies primary limit has tripped. If limit continues to Primary limit switch cycling
trip, verify that heater is not overheating. Verify sufcient
airow and proper ductwork connections. NOTE: dual
blower units have two heater racks and two primary limits.
28
ENVIRO-TEC
SECTION SIX - INSPECTION & START-UP CHECKLIST
RECEIVING & INSPECTION
Unit received undamaged
q
Unit arrangement/handing correct
q
HANDLING & INSTALLATION
Unit mounted level & square
q
Proper electrical service provided
q
Proper service switch/disconnect provided
q
Proper chilled water line sized to unit
q
Proper refrigerant line sized to unit
q
Proper steam condensate trap on return line
q
All services to unit in code compliance
q
COOLING/HEATING CONNECTIONS
Protect Valve Package Components From Heat
q
Connect Field Piping To Unit
q
Install Drain Line & Traps As Required
q
Install Condensate Pan under Piping as Required
q
Unit received complete as ordered
q
Unit structural support complete & correct
q
Proper access provided for unit & accessories
q
Proper overcurrent protection provided
q
Proper hot water line to unit
q
Proper steam line sizes to unit
q
Proper steam supply pressure to unit (15psi max)
q
All shipping screws & braces removed
q
Mount any eld provided valve packages
q
Pressure test all piping for leaks
q
Insulate all piping as required
q
DUCTWORK CONNECTIONS
Install Ductwork, Fittings & Grilles As Required
q
Control Outside Air For Freeze Protection
q
ELECTRICAL CONNECTIONS
Refer to unit wiring diagram
q
All eld wiring in code compliance
q
UNIT STARTUP
General visual unit & system inspection
q
Record ambient temperature
q
Close all unit isolation valves
q
Fill systems with water/refrigerant
q
All ductwork & grilles in place
q
Start fans, etc.
q
Check all ductwork & units for air leaks
q
Record all nal settings for future use
q
Check all dampers for proper operation
q
Verify proper heating operation
q
Proper supply & return grille type & size used
q
Insulate all ductwork as required
q
Connect incoming power service or services
q
Tighten all wiring connections before applying power.
q
Record electrical supply voltage
q
Check all wiring for secure connections
q
Flush water systems
q
Vent water systems as required
q
All unit panels & lters in place
q
Check for overload condition of all units
q
Balance air systems as required
q
Check piping & ductwork for vibration
q
Verify proper cooling operation
q
Reinstall all covers & access panels
q
BLOWER/MOTOR
Check blower wheel set screw tightness
q
ENVIRO-TEC
Check blower speed as necessary for balancing airow
q
29
ENVIRO-TEC is a mark and/or registered mark. Unauthorized use is strictly prohibited.
Catalog: ET115.24-NOM12 (718) © 2018 Johnson Controls www.enviro-tec.com
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