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Part #457831
VSU Make-Up Air Unit
® ®
Installation, Operation and Maintenance Manual Installation, Operation and Maintenance Manual
Please r Please read and save these instructions. Read car ead and save these instructions. Read carefully befor efully before attempting to assemble, install, operate or maintain the e attempting to assemble, install, operate or maintain the
pr product described. Pr oduct described. Protect yourself and others by observing all safety information. Failur otect your
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Receiving Inspection and Maintenance during Storage Upon receiving the product check to make sure all While in storage, inspect fans once per month. Keep a items are accounted for by referencing the bill of record of inspection and maintenance performed. lading to ensure all items were received. Inspect If moisture or dirt accumulations are found on parts, each crate for shipping damage before accepting the source should be located and eliminated. At each delivery. Notify the carrier if any
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Table of Contents Installation Installation 1. Filter/Stand Section Filter/Stand Section . . . . . . . . . . . . . . . . . . . . . .3-4 The unit should be mounted on a concrete slab four Burner/Blower Section ..................... 4 inches thick with a proper gravel drainage bed. Allow Ductwork ................................ 4 one foot on each side of the unit as shown in the Dimensional Data . . . . . . . . . . . . . . . . . . . . . . . . . 5 Concrete Slab and Unit Footprint drawing below
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4. Complete Installation Installation continued A typical horizontal discharge installation is shown. 2. Burner/Blower Section Gas and/or electrical lines can be connected at this Use a crane and a spreader bar hooked to the factory time. lifting lugs (shown below) to lift and center the unit For upblast units, a duct elbow may be needed to onto the filter stand section. The sections can be turn the ductwork into the building. Follow proper caulked together, but it is not needed with t
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Dimensional Data Upblast Discharge Elevation View F H K Lifting Lugs C Electrical Controls J A E Gas Controls* 24^ B *Direct Gas units only ^Standard factory clearance. Additional stand heights are available from the factory. Unit Dimensional Data Blower Dimensional Data Unit Weight Housing Blower A B C E Filters F H J K Blower/Heater* Stand/Filter Size Size 40 111 54 95 144 (20) 20x25 220 26 20 68 12 2000 lbs. 700 lbs. All dimensions are shown in inches. * Weights will vary with blower and hor
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1. Determine the Supply Gas Installation of Direct Gas Piping Requirements The unit’s direct gas nameplate states the requirements IMPORTANT for the gas being supplied to the unit. The direct gas All gas piping must be installed in accordance nameplate is located on the outside of the unit on the with the latest edition of the National Fuel Gas control center side. Minimum gas pressure for Code ANSI/Z223.1 and any local codes that may maximum output apply. In Canada, the equipment shall
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4. Pipe the Optional Vent Line If an optional vent line is located between the safety shutoff valves it must be piped to the outdoors. WARNING Reference the National Fuel Gas Code for additional vent line requirements. Vent Line Solenoid To Outdoors To Burner From Supply Safety Shut-off Valves Optional Vent Line 5. Test the System for Leaks Check both the supply lines and the factory piping for leaks. Apply a soap and water solution to all piping and watch for bubbling which indicates a le
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2. Check the Blower Rotation Start-Up - Blower Open the blower access door Refer to the Start-Up Checklist in the Reference and run the blower momentarily section before proceeding further! to determine the rotation. Arrows are placed on the Pre Start-Up Check blower scroll to indicate the Rotate the fan wheel by hand and make sure no parts proper direction or reference Blower are rubbing. Check the V-belt drive for proper alignment Housing the example shown to the right. and tension (a
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5. Air Volume Measurement & Check Measure the unit’s air volume (cfm) and compare it with it’s rated air volume. If the measured air volume is off, adjust the fan’s RPM by changing/adjusting the drive. NOTE The most accurate way to measure the air volume is by using a pitot traverse method downstream of the blower. Other methods can be used, but should be proven and accurate. IMPORTANT Changing the air volume can significantly increase the motor’s amps. If the air volume is changed, the
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3. Set the Burner Air Pressure Differential Start-Up Direct Gas With the fan running and discharging 70ºF (21ºC) air, connect a U-Tube manometer to the outer sensing IMPORTANT probes (see below) and measure the static pressure For proper unit function and safety, follow the start- across the burner. up procedure in the exact order that it is presented. 9 Outer Sensing Probes IMPORTANT This start-up should begin after all of the installation 8 procedures and the blower start-up have been co
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4. Set the Maximum Firing Rate Regulators and Modulating Valves Monitor the unit’s actual temperature rise by placing Remove one wire to Remove cap to access a thermocouple in the unit’s inlet and a second in the send the unit to the maximum firing rate discharge, three duct diameters downstream of the minimum firing rate adjustment burner. Send the unit to maximum fire by disconnecting and isolating the wire connected to Terminal 4 on the Maxitrol 14. While monitoring the units tempe
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6. Set the Unit’s Operating Temperature Set the operating temperature. The operating temperature setting depends on which Maxitrol controller is used. Maxitrol Series 14 The Maxitrol Series 14 should be set to the desired discharge temperature. The temperature selector is built into the amplifier. Set the discharge temperature Typical: 65ºF Series 14 Discharge Temperature Setting 7. Flame Signal Check To measure the flame signal connect a standard DC voltmeter to the flame amplifier tes
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Operation - Electrical Electrical Sequence Direct Gas Burner Sequence 1. Supply Fan Contact (S2) Closed 1. Supply Fan Contact Closed • Power passes to damper which opens • Power passes to the supply fan and heat switch • When damper is fully opened, damper relay 2. Heat Contact Closed (D1) is energized an optional N.O. damper limit • Power passes to the heat relay then to the switch (DL1) closes Flame Safeguard • Power passes through a N.C. fault contact on 3. Flame Safeguard (FSG) Seque
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Troubleshooting Blower Does Not Operate 115 VAC between No Check Main Voltage terminals 102 and 101? (See Blower Start-Up Step #1) Main Disconnect (DS1) Off (Turn Main Disconnect DS1 On) Yes Primary Fuses Blown (Replace Fuses) Main Transformer Defective (Replace Transformer) 24 VAC between No terminals R and X? Yes Main Transformer Defective (Replace Transformer) 24 VAC between No terminals G and X? Yes Supply Switch (S2) Off (Turn Supply Switch (S2) On) 24 VAC between No terminals 7 and X? Yes
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Troubleshooting Heater Does Not Operate Does not attempt to light (No visible spark) No 24 VAC between terminals W1 and X? Heat Switch (S4) Off Yes (Turn Heat Switch (S4) On) Heat Switch Not Wired (Wire Heat Switch (S4)) No 115 VAC between terminals 102 and 101? Primary Fuses Blown Yes (Replace Fuses) Main Transformer (TR4) Defective (Replace Transformer) No 115 VAC between terminals 103 and 101? Inlet Air Sensor (TS) Holding Yes (Adjust TS setting — Reference Blower Start-Up Step #6) Heat R
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Troubleshooting Heater Does Not Operate Attempts to light, but no pilot (visible spark) Check inlet gas pressure. Note: The minimum and maximum gas pressures (Direct Gas Start-Up Step #1) for your unit are shown on the direct gas label. (Reference Direct Gas Start-Up – Step #1) Yes Gas pressure between the No minimum and maximum shown on the direct gas label? Correct gas pressure (Reference Direct Gas Start-Up – Step #1) Yes Air in the gas line? Purge gas line (Verify gas at the pilot) No Ch
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Troubleshooting Heater Does Not Operate Visible pilot Measure the flame signal Note: The flame signal should be steady and when there is a visible pilot above 1.25 VDC with a visible pilot. (Reference Direct Gas Start-Up – Step #7) Flame signal greater No than 1.25 VDC Unit is not grounded (Properly ground unit) Flame rod is grounding out (Adjust the flame rod to avoid contact with the burner or the unit) Yes Cracked porcelain on flame rod (Replace flame rod) Check for proper airflow (Direct
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Maintenance - Routine Motors CAUTION Motor maintenance is generally limited to cleaning Lock-out the gas and the electrical power to the and lubrication (where applicable). unit before performing any maintenance or service Cleaning should be limited to exterior surfaces only. operations to this unit. Removing dust and grease build-up on the motor assures proper motor cooling. V-Belt Drives V-belt drives must be checked on a regular basis for Motors supplied with grease fittings should be w
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Maintenance - Fall Bearings Start-Up Repeat the Blower Start-Up Step #5 and Direct Gas Start- The bearings for Greenheck fans are carefully selected Up Steps #1 through #4. This will ensure that the gas and to match the maximum load and operating conditions air are set properly before the heating season begins and of the specific class, arrangement and fan size. The should lead to trouble free operation all winter. instructions provided in this manual and those provided by the bearing manu
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Reference Typical Control Center Layout 1 5 2 7 3 4 6 12 8 9 10 11 1. Spark Generator 7. Motor Fuses 2. Temperature Selector 8. Heating Inlet Air Switch 3. Amplifier 9. Flame Safeguard 4. 24V Transformer 10. High Limit Switch 5. 120V Transformer 11. Disconnect 6. Transformer Fuses 12. Soft Start Typical Gas Train Layout 1. Spark Generator 2. Temperature Selector High/Low Airflow Switch* View Port Gas Pressure 3. Amplifier 4. 24V Transformer Pilot Solenoid 5. 120V Transformer Modulating V
