Accurex XDG Installation, Operation And Maintenance Manual

Direct gas make-up air

Hide thumbs

Table Of Contents

Table of Contents

Quick Links

Installation, Operation and Maintenance Manual

Please read and save these instructions for future reference. Read carefully before attempting to assemble, install,

operate or maintain the product described. Protect yourself and others by observing all safety information. Failure

to comply with instructions will result in voiding of the product warranty and may result in personal injury and/or

property damage.

General Safety Information

Only qualified personnel should install this unit.

Personnel should have a clear understanding of these

instructions and should be aware of general safety

precautions. Improper installation can result in electric

shock, possible injury due to coming in contact with

moving parts, as well as other potential hazards. Other

considerations may be required if high winds or seismic

activity are present. If more information is needed,

contact a licensed professional engineer before moving

forward.

1. Follow all local electrical and safety codes, as well

as the National Electrical Code (NEC), the National

Fire Protection Agency (NFPA), where applicable.

Follow the Canadian Electrical Code (CEC) in

Canada.

2. The rotation of the supply fan wheel is critical. It

must be free to rotate without striking or rubbing

any stationary objects.

3. Motor must be securely and adequately grounded.

4. Do not spin fan wheel faster than the maximum

cataloged fan rpm. Adjustments to fan speed

significantly affects motor load. If the fan RPM is

changed, the motor current should be checked to

make sure it is not exceeding the motor nameplate

amps.

5. Do not allow the power cable to kink or come in

contact with oil, grease, hot surfaces, or chemicals.

Replace cord immediately if damaged.

6. Verify that the power source is compatible with the

equipment.

7. Never open fan access doors while the fan is

running.

DANGER

Always disconnect power before working

on or near a unit. Use appropriate lockout

tagout procedures to prevent accidental

power up.

CAUTION

When servicing the unit, motor may be hot

enough to cause pain or injury. Allow motor

to cool before servicing.

FOR YOUR SAFETY

If you smell gas:

1. Open windows.

2. Do not touch electrical switches.

3. Extinguish any open flame.

4. Immediately call your gas supplier.

FOR YOUR SAFETY

The use and storage of gasoline or other

flammable vapors and liquids in open

containers in the vicinity of this appliance is

hazardous.

WARNING

Improper installation, adjustment, alteration,

service or maintenance can cause

property damage, injury or death. Read the

installation, operating and maintenance

instructions thoroughly before installing or

servicing this equipment.

Document 482887

Models XDG, XDGX

Direct Gas Make-Up Air

Table of Contents

Summary of Contents for Accurex XDG

Page 1 Document 482887 Models XDG, XDGX Direct Gas Make-Up Air Installation, Operation and Maintenance Manual Please read and save these instructions for future reference. Read carefully before attempting to assemble, install, operate or maintain the product described. Protect yourself and others by observing all safety information. Failure to comply with instructions will result in voiding of the product warranty and may result in personal injury and/or property damage.
Page 2: Table Of Contents
Table of Contents General Start-Up: Direct Gas-Fired Heating Receiving ........3 All Units .
Page 3: General
General temperature. Leave coverings loose to permit air Receiving circulation and to allow for periodic inspection. This product may have been subject to road salt The unit should be stored at least 3½ in. (89 mm) off during transit. If so, immediately wash off all visible the floor.
Page 4: Model Number Code
* 67 in. (170 cm) when equipped with evaporative cooling module options selected. ** 61 in. (155 cm) when equipped with evaporative cooling module over 4800 cfm Note: If XDG-H05 is equipped with an evaporative cooling module, access to the filters, media, sump, and water connections is accomplished through the roof of the evaporative 36 inches (91.4 cm)
Page 5: Duct Sizes
Installation Duct Sizes See charts for duct sizes and straight duct lengths recommended for optimal performance based on AMCA Publication 201-90. Using duct sizes less than recommended will affect fan performance. Follow good duct installation practices for the remaining ductwork. Forward Curved Fans (Horizontal Units) Straight Model...
Page 6: Indoor Unit Mounting
Spreader Bar 2. Install TSU Uni Use a crane and sp are provided as sho Installation It is highly recomm and attached after Unit may be fasten Indoor Unit Mounting Lifting Lugs (4) Hanging Floor Mounted When suspending a unit indoors, adequate structural 1.
Page 7: Outdoor Unit Mounting
Installation Outdoor Unit Mounting Standard Curb 1. Install Curb and/or Equipment/Leg Support(s) 4. Install Unit Position curb and/or equipment/leg support(s) on Use a crane and a set of spreader bars hooked to the the roof (reference the unit submittal for placement factory lifting lugs to lift and position the unit on the in relation to the unit).
Page 8: Combination Curb
Installation Outdoor Unit Mounting Combination Curb 1. Install Curb and Equipment/Leg Support(s) 3. Install Ductwork Position curb and equipment/leg support(s) on the roof Follow good duct practices for all ductwork. Install (reference the unit submittal for placement in relation ductwork in accordance with SMACNA and AMCA to the unit).
Page 9 Installation Outdoor Unit Mounting Combination Curb (continued) 5. Install Exhaust Fan 8. Assemble and Attach Shipped loose Modules Fasten exhaust fan to curb extension using appropriate Using sheet metal screws, assemble optional shipped methods. Installing the exhaust fan prior to the loose modules.
Page 10: Slab Mounted
Installation Outdoor Unit Mounting 1. Slab Construction Slab Recommended Size is 1 ft wider and longer than total unit size. Rail Recommended Material is concrete at least 4” thick. Slab should be set level on a sufﬁcient bed of gravel for proper drainage. 1.
Page 11: Optional Component Mounting
Installation Optional Component Mounting Evaporative Cooling Module Diffuser Note: Small evaporative cooling module will ship The location of the discharge diffuser is critical for attached to the base unit from the factory and will optimum performance of the system. not require any additional fixation to the base unit as Using self-tapping screws, attach diffuser to the illustrated below.
Page 12: Line Voltage Electrical Wiring
Installation Line Voltage Electrical Wiring 2. Provide the Opening(s) for the Electrical Before connecting power to the unit, read and understand the following instructions and wiring Connections diagrams. Complete wiring diagrams are attached on Electrical openings vary by unit size and arrangement the inside of the control center door(s).
Page 13: Optional Electrical Accessory Wiring
Installation Optional Electrical Accessory Wiring Evaporative Cooling Module Fire Suppression System 1. Auto Drain and Fill Valves The building fire suppression system is typically wired to shut down the unit in the event of a fire. A normally The unit may have been provided with the auto drain closed (NC) contact should be wired in series with and fill option.
Page 14: Room Temperature Sensing Devices
Installation Optional Electrical Accessory Wiring Room Temperature Sensing Devices One of the following sensors or equivalent may have been provided and will require field wiring. Refer to the unit wiring diagram for terminal designations. If a microprocessor is included with this unit, reference the supplemental Microprocessor Controller for Make-Up Air Reference Guide for more information.
Page 15: Piping
Installation Piping 2. Install Additional Regulator if Required All gas piping must be installed in accordance with the latest edition of the National Fuel Gas Code ANSI/ When the supply gas pressure exceeds the maximum Z223.1 and any local codes that may apply. In Canada, gas pressure shown on the direct gas nameplate, an the equipment shall be installed in accordance with additional regulator is required to reduce the pressure.
Page 16: Optional Evaporative Cooling Module
Installation Piping Optional Evaporative Cooling Module Recirculating Pump Single Pass Supply Line Supply Line Sump Overﬂow VALVE A Field-Supplied Supply Solenoid Sump Drain Supply Line Valve Field-Supplied (normally closed) Drain Line Valve Drain Line Overﬂow VALVE B Trap Trap Supply Line Drain Solenoid (normally open) Drain Line Auto Drain and Fill...
Page 17: Optional Evaporative Cooling Module
Installation Piping Optional Evaporative Cooling Module (continued) 1. Install the Water Supply Line 3. Check/Adjust Water Level Supply line opening requirements vary by unit size and Check the water level in the sump tank. The water level arrangement. Connect the water supply line to the float must be above the pump intake and below the overflow.
Page 18: Optional Split Direct Expansion Coil
Installation Piping Optional Split Direct Expansion (DX) Coil Guidelines for the installation of direct expansion (DX) Coil Suction Header cooling coils have been provided to ensure proper Distributor Liquid Line Equalizer Line performance and longevity of the coils. These are general guidelines that may have to be tailored to Nozzle meet the requirements of a specific installation.
Page 19: Optional Chilled Water Coil
Installation Piping Optional Chilled Water Coil 2. Connect the Supply & Return Lines Guidelines for the installation of chilled water cooling coils have been provided to ensure proper performance Connect the supply and return lines as shown. and longevity of the coils. These are general guidelines 3.
Page 20: Optional Components
Installation Optional Components Building Pressure Control Duct Pressure Control 1. Mounting Pressure Sensor The optional microprocessor controller can be selected Using the factory provided bracket, mount the pressure to modulate the supply fan based upon a comparison sensor outside of the of the duct static pressure set point to the actual building.
Page 21: Supply Fan
XDGX - P1 2 0 - H32 - MF Backward-curved plenum fans are single width, single inlet fans. The impellers are Model Parent Mixed Flow unhoused, with blades that XDG and XDGX Housing Size curve away from the direction of 10-50 rotation. These fans throw the Optional Fan Wheel Diameter (in.)
Page 22: Pre-Start Checks
Supply Fan Pre-Start Checks 4. Check Plenum Fan Radial Overlap, Offset, TOOLS REQUIRED Gap, and Wheel Alignment (if applicable) • Voltage Meter (with wire probes) Backward-Curved Plenum Fan Radial Overlap • Amperage Meter Proper wheel and inlet cone overlap is shown in the •...
Page 23: Start-Up
Supply Fan Start-Up 1. Check Voltage 3. Check for Vibration Before starting the unit, compare the supplied voltage, Check for unusual noise, vibration or overheating of the hertz, and phase with the unit and motor(s) nameplate bearings. information. Excessive vibration may be experienced during the 2.
Page 24: Pre-Start: Direct Gas-Fired Heating
Pre-Start: Direct Gas-Fired Heating Ignition Control Identification Industrial Pilot Commercial Pilot Typical ignition control for industrial pilot. Typical ignition control for commercial pilot. • All Industrial Pilot Systems are 120V • A 24V Commercial Pilot System is used with 6-inch burners •...
Page 25 Pre-Start: Direct Gas-Fired Heating Gas Train Identification Typical Pilot System with Separate Modulating Valve and Regulator Burner Differential Pilot Solenoid Pressure Sensor Pilot Gas Pressure Pilot Regulator Test Port Airﬂow (Optional) Low Gas Modulating Pressure Switch Valve Burner Manual Shut-Off Valve (Optional) High Gas Manual Pilot Pressure Switch...
Page 26: Accessory Identification
Pre-Start: Direct Gas-Fired Heating Accessory Identification Temperature Control Identification Maxitrol 44 Series Amplifier There are multiple control methods available for controlling the burner firing rate depending upon which This system is used to maintain a room temperature set Maxitrol System was supplied with the unit. Identify the point when a call for heat is active.
Page 27: High/Low Gas Pressure Switches(Es)
Pre-Start: Direct Gas-Fired Heating Accessory Identification Temperature Control Identification High/Low Gas Pressure Switch(es) (continued) An optional high and/or low gas pressure switch(es) may have been provided with the unit. The location of these Maxitrol SC Series Amplifier switches is shown in the Pre-Start-Up: Direct Gas- This system requires that an analog control signal be Fired Heating, Gas Train Identification section in this provided to control the burner firing rate.
Page 28: Start-Up: Direct Gas-Fired Heating
Start-Up: Direct Gas-Fired Heating All Units 6. Set the Burner Air Pressure Differential For proper unit function and safety, follow the start-up procedure in the exact order that it is presented. For units equipped with recirculation, reference the Start-Up: Direct Gas-Fired Heating, Optional Features, This start-up should begin after all of the installation Recirculation Operation section in this Installation, procedures and the supply fan start-up have been...
Page 29: All Units
Start-Up: Direct Gas-Fired Heating All Units Adjust fan RPM via adjustable motor sheaves (if equipped), VFD (if equipped) or sheave replacement to achieve proper burner pressure drop. Motor amp draw must not exceed Full Load Amperage (FLA) on motor nameplate. If fan RPM cannot be adjusted, evenly adjust the baffles above and below the burner, keeping the burner centered in the opening until the required pressure is obtained.
Page 30: Industrial Pilot System (>12-Inch Burner)
Start-Up: Direct Gas-Fired Heating 120V Industrial Pilot System (12-inch burner or greater) 1. Energize the heating Minimum firing Maximum firing rate adjustment rate adjustment Connect terminals R to W1. 2. Set pilot gas pressure Close main hand valve, then set the pilot gas pressure to 1.5 - 3 in.
Page 31: Commercial Pilot System (>12-Inch Burner)
Start-Up: Direct Gas-Fired Heating 120V Commercial Pilot System (12-inch burner or greater) 1. Energize the heating Minimum firing Maximum firing rate adjustment rate adjustment Connect terminals R to W1. 2. Set pilot flame signal Close main hand valve. Flame current must be measured with pilot valve lit but no main gas flowing.
Page 32: Commercial Pilot System (6-Inch Burner)
Start-Up: Direct Gas-Fired Heating 24V Commercial Pilot System (6-inch burner) 1. Energize the heating 4. Set the minimum firing rate Connect terminals R to W1. Set the minimum firing rate to achieve a small ribbon of continuous blue flame across the burner. 2.
Page 33: Final Checks
Start-Up: Direct Gas-Fired Heating Final Checks 1. Set the Unit’s Operating Temperature Maxitrol SC Series Place jumpers and DIP switches as shown. If VDC input Set the operating temperature. The operating signal is supplied, all three DIP switches must be placed temperature setting depends on which Maxitrol in the “OFF”...
Page 34: Optional Features
Start-Up: Direct Gas-Fired Heating Optional Features Variable Air Volume (VAV) Pressure Indicating Pressure Setting Complete the Supply Fan Pre-Start Checks and Needle Needles Start-Up sections in this Installation, Operation and Maintenance Manual before proceeding. For maintenance issues associated with a variable frequency drive (VFD), consult the drive’s manual supplied with the unit.
Page 35 Start-Up: Direct Gas-Fired Heating Optional Features Variable Air Volume (VAV) (continued) minimum airflow, the bypass damper will be mostly closed and a majority of the air will pass though the burner profile. In this way, the airflow through the burner profile remains relatively constant through the range of airflow operation.
Page 36: Recirculation Operation
Start-Up: Direct Gas-Fired Heating Optional Features Recirculation Operation The recirculation operation option is recommended Pressure Indicating Pressure Setting Needle Needles when the ventilation equipment provides the primary source of heating for the space or when exhaust fan tracking is required. A minimum of 20% outdoor air is mixed with up to 80% recirculated air.
Page 37: Recirculation Arrangements
Start-Up: Direct Gas-Fired Heating Optional Features Recirculation Arrangements Burner Pressure Differential Check There are two important design features that must be maintained by recirculating direct fired equipment. The burner pressure differential on direct fired units Recirculated air cannot be passed over the burner with recirculation is affected by total airflow and the and airflow across the burner must remain constant percentage of airflow that is passing over the burner.
Page 38: Start-Up: Optional Features Evaporative Cooling Module
Start-Up: Optional Features Evaporative Cooling Module 7. Adjust the Water Bleed-Off Rate Note: For single pass, complete steps 1, 4, 5 and The water bleed-off rate is dependent on the water’s 6 only. mineral content. After two weeks of service, adjust 1.
Page 39: Other
Start-Up: Optional Features Other Building Freeze Protection Dirty Filter Switch This option is intended to disable the unit supply fan To adjust the switch, the unit must be running with all of in the event the discharge temperature falls below the access doors in place, except for the compartment 35°F for five minutes.
Page 40: Sequence Of Operation
Sequence of Operation If the unit has a microprocessor, reference the Commercial Flame Safeguard Ignition Sequence supplemental Microprocessor Controller for Make-Up • Power passes to normally closed high limit control Air Reference Guide for more information. contact (HLC1) which is closed if temperature has OPTIONAL EXHAUST remained below set point.
Page 41: Optional Cooling
Sequence of Operation OPTIONAL COOLING Freeze Condition • If the incoming air temperature is below the Optional Cooling Contact (S4) Closed evaporative cooling module freeze sensor (FRZ) set • Power passes to normally open fan relay (RF or point, the freeze sensor (FRZ) contacts will open, ST1) which is energized and closed.
Page 42: Optional Variable Air Volume
Sequence of Operation OPTIONAL VARIABLE VOLUME Building Pressure VFD Control Two Speed VFD Control • When the supply fan relay (RF) is energized, the normally open supply fan relay (RF) contacts are • When the supply fan relay (RF) is energized, the closed.
Page 43: Optional Recirculation
Sequence of Operation OPTIONAL RECIRCULATION Building Pressure Recirculation Control Two Position Recirculation Control • Power passes to inlet damper which opens. • When damper is fully opened, normally open • Power passes to inlet damper which opens. damper limit switch (DL1) closes. •...
Page 44: Optional Night Setback
Sequence of Operation OPTIONAL NIGHT SETBACK Night Setback Schedule • The night setback schedule is established within the programmable thermostat on the remote panel. The schedule must be set for the occupied and unoccupied hours of the controlled space. Night Setback Fan Control •...
Page 45: Maintenance General
Maintenance General Bearings (if applicable) CAUTION Lock-out the gas and the electrical power to the Fan bearings are carefully selected to match the maximum load and operating conditions of the specific unit before performing any maintenance or service class, arrangement and fan size. The instructions operations to this unit.
Page 46: Motors
Maintenance General Motors Evaporative Cooling Module Motor maintenance is generally limited to cleaning and The media must periodically be brushed lightly with lubrication (where applicable). a soft bristle brush in an up and down motion while flushing with water. This aids in reducing the amount of Limit cleaning to exterior surfaces only.
Page 47: Heating/Cooling
Maintenance Heating/Cooling Start-Up Repeat Supply Fan, Pre-Start Checks and Start-Up; Pre-Start: Direct Gas-Fired Heating; and Start-Up: Direct Gas-Fired Heating sections in this Installation, Operation and Maintenance Manual. This will ensure that the gas and air are set properly before the heating season begins and should lead to trouble free operation all winter.
Page 48: Troubleshooting
Troubleshooting Supply Fan Problem: Fan does not operate. Main incoming power not connected. Connect proper supply Line voltage across L1 & L2, L2 & L3, No  and L1 & L3 on main disconnect (DS1)? power to unit.  Line voltage across T1 & T2, T2 & T3, Main disconnect (DS1) open or defective.
Page 49 Troubleshooting Supply Fan Problem: Motor overamps. Motor voltage correct? No  Provide proper power supply. Reference Supply Fan, Start-Up.  Fan rotation correct? Reverse fan rotation. Reference Supply Fan, Start-Up. No   Adjust drives or increase external static pressure as needed. Air volume too high? Yes ...
Page 50: Direct Gas-Fired Heat
Troubleshooting Direct Gas-Fired Heat Problem: Heater does not operate (120V industrial pilot: 12-inch burner or greater). Is fan operating correctly? Refer to Troubleshooting, Supply Fan. No   Heat switch (S4) off. Turn heat switch (S4) on. Heat switch not wired. Wire heat switch (S4). 24 VAC between terminals W1 and C? No ...
Page 51 Troubleshooting Direct Gas-Fired Heat Pressure drop across the burner Adjust fan speed and/or burner baffles to achieve between 0.625 - 0.675 in. wg for 0.625 - 0.675 in. wg for natural gas (0.8 - 0.9 in.wg for LP gas) No  ...
Page 52 Troubleshooting Direct Gas-Fired Heat Problem: Heater does not operate (120V commercial pilot: 12-inch burner or greater). Is fan operating correctly? No  Refer to Troubleshooting, Supply Fan.  Heat switch (S4) off. Turn heat switch (S4) on. Heat switch not wired.Wire heat switch (S4). 24 VAC between terminals W1 and C? No ...
Page 53 Troubleshooting Direct Gas-Fired Heat Steady green light illuminated on Skip to question that reads, 115 VAC between terminals 110 Yes  flame safeguard (FSG)? and 101?  Flame rod dirty or corroded? Yes  Clean flame rod. Remove corrosion with emery cloth. ...
Page 54 Troubleshooting Direct Gas-Fired Heat Problem: Heater does not operate (24V commercial pilot: 6-inch burner). Is fan operating correctly? No  Refer to Troubleshooting, Supply Fan.  Heat switch (S4) off. Turn heat switch (S4) on. Heat switch not wired. Wire heat switch (S4). 24 VAC between terminals W1 and C? No ...
Page 55 Troubleshooting Direct Gas-Fired Heat Flame wire broken. Replace wire. Electrical continuity from control center Connection at flame rod boot failed. Repair connection. No  end of flame wire to flame rod boot?  Flame rod boot corroded. Replace flame rod boot. Shield or spare wire touching flame wire in flame rod boot.
Page 56 Troubleshooting Direct Gas-Fired Heat Problem: Heater does not modulate correctly. Maxitrol 14 Series system. Is fan operating correctly? No  Refer to Troubleshooting, Supply Fan.  Is the burner operating and lit? Refer to Troubleshooting, Direct Gas-Fired Heat. No  ...
Page 57 Troubleshooting Direct Gas-Fired Heat Problem: Heater does not modulate correctly. Maxitrol 44 Series system. Is fan operating correctly? No  Refer to Troubleshooting, Supply Fan.  Is the burner operating and lit? Refer to Troubleshooting, Direct Gas-Fired Heat. No  ...
Page 58: Direct Gas-Fired Heat
Troubleshooting Direct Gas-Fired Heat Problem: Heater does not modulate correctly. Maxitrol SC Series system. Is fan operating correctly? No  Refer to Troubleshooting, Supply Fan.  Is the burner operating and lit? Refer to Troubleshooting, Direct Gas-Fired Heat. No  ...
Page 59: Evaporative Cooling
Troubleshooting Evaporative Cooling Problem: Evaporative Cooling Module Does Not Operate - Recirculating Pump Control Is fan operating correctly? No  Refer to Troubleshooting, Supply Fan.  Cool switch (S4) off. Turn cool switch (S4) on. Cool switch not wired. Wire cool switch (S4). 24 VAC between terminals Y1 and C No ...
Page 60 Troubleshooting Evaporative Cooling Problem: Evaporative Cooling Module Does Not Operate - Auto Drain and Fill Control Is fan operating correctly? No  Refer to the Troubleshooting, Supply Fan.  Cool switch (S4) off. Turn cool switch (S4) on. Cool switch not wired. Wire cool switch (S4). 24 VAC between terminals Y1 and C No ...
Page 61: Evaporative Cooling
Troubleshooting Evaporative Cooling Problem: Evaporative Cooling Module Does Not Operate - Single Pass Control Is fan operating correctly? No  Refer to the Troubleshooting, Supply Fan.  Cool switch (S4) off. Turn cool switch (S4) on. Cool switch not wired. Wire cool switch (S4). 24 VAC between terminals Y1 and C No ...
Page 62: Reference
Reference Typical Control Center Layout 1. Supply Motor Starter — 24 volt magnetic contacts 15. Remote Temperature Selector (optional) — for starting supply motor. allows for remote temperature set point. 2. Supply Overload — provides electronic overload 16. Heat Relay — allows power to pass to heating protection to supply motor.
Page 63: Start-Up Checklist
Reference Start-Up Checklist Start-Up Direct Gas Unit Model Number ________________________________ (e.g. XDGX-120-H32) Refer to Start-Up: Direct Gas-Fired Heating section for further detail. o Check supply gas pressure Unit Serial Number _________________________________ (e.g. 10111000) _________ Maximum _________ Minimum Start-Up Date _____________________________________ _________ Actual Start-Up Personnel Name __________________________ o Set optional High Gas Pressure Switch...
Page 64: Maintenance Log
As a result of our commitment to continuous improvement, Accurex reserves the right to change specifications without notice. Specific Accurex product warranties are located on accurex.com within the product area tabs and in the Library under Warranties. P.O. Box 410 Schofield, WI 54476 Phone: 800.333.1400 •...

This manual is also suitable for:

Xdgx