Standard and Modular Direct Fired Heaters Installation, Operation, and Maintenance Manual Modular Direct Fired Heater Standard Direct Fired Heater FOR YOUR SAFETY If you smell gas: 1. Open windows. 2. Don’t touch electrical switches. 3. Extinguish any open flames. 4. Immediately call your gas supplier. Direct Fired Module 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.
TABLE OF CONTENTS WARRANTY ...................................................................................................................................................................................... 4 INSTALLATION ................................................................................................................................................................................. 5 Mechanical ................................................................................................
WARRANTY This equipment is warranted to be free from defects in materials and workmanship, under normal use and service, for a period of 12 months from date of shipment. This warranty shall not apply if: 1. The equipment is not installed by a qualified installer per the MANUFACTURER’S installation instructions shipped with the product, 2. The equipment is not installed in accordance with federal, state and local codes and regulations, 3. The equipment is misused or neglected, 4.
INSTALLATION It is imperative that this unit is installed and operated with the designed airflow, gas, and electrical supply in accordance with this manual. If there are any questions about any items, please call the service department at 1-866-784-6900 for warranty and technical support issues. Mechanical WARNING: DO NOT RAISE VENTILATOR BY THE INTAKE HOOD, BLOWER OR MOTOR SHAFT, OR BEARINGS – USE LIFTING LUGS PROVIDED OR A SLING Site Preparation 1.
surface. Be sure duct connection and fan outlet are properly aligned and sealed. Secure fan to curb through vertical portion of the ventilator base assembly flange using a minimum of eight (8) lug screws, anchor bolts, or other suitable fasteners (not furnished). Shims may be required depending upon curb installation and roofing material. Check all fasteners for tightness. The diagrams below show different mechanical installation configurations.
Direct Fired Module Installation Indoor (INLINE) Installation Heat Module Add-On Installation Modular heat units shipped to add heat onto existing blower only applications require field mechanical and wiring installation. 1. Remove existing filter intake and lifting lugs from blower section intake side. 2. Attach heat module to blower intake using the provided sheet metal screws and bolts. Tighten screws and bolts securely to compress the gasket between the heat module and the blower module. 3.
Gas Installation of gas piping must conform with local building codes, or in the absence of local codes, with the National Fuel Gas Code, ANSI Z223.1 (NFPA 54) – latest edition. In Canada, installation must be in accordance with CAN/CGA-B149.1 for natural gas units and CAN/CGA-B149.2 for propane units. WARNING: INLET GAS PRESSURE MUST NOT EXCEED PRESSURE INDICATED ON NAMEPLATE. SEE UNIT NAMEPLATE FOR PROPER GAS SUPPLY PRESSURE AND GAS TYPE. 1. Always disconnect power before working on or near a heater.
Electrical Before connecting power to the heater, read and understand this entire section of this document. As-built wiring diagrams are furnished with each fan by the factory, and are attached to the door of the unit. WARNING!! Disconnect power before installing or servicing fan. High voltage electrical input is needed for this equipment. This work should be performed by a qualified electrician.
PSC (Permanent Split Capacitor) Motor Speed Control Some single phase direct drive fans contain speed controls that regulate the amount of voltage going to the motor. Specific PSC motors must be used in conjunction with speed controls. The speed control has a knob with an off position, and high to low range. At high speed, the speed control allows all of the line voltage to pass right to the motor. A minimum speed adjustment is provided to allow independent control of the minimum speed setting.
Remote Control Panel BK BK OR OR WH WH GY GY BR BR RD RD PK PK YW YW RD RD BK BK BK BK OR OR WH WH GY GY BR BR RD RD PK PK YW YW RD RD BK BK BL Fan to Building Wiring Connection 11 C NO NC On units shipped with the optional remote control panel, an electrical drop containing the panel wiring is provided with the heater. There is a terminal strip inside the remote panel that matches the terminals in the heater unit.
OPERATION Prior to starting up or operating the heater, check all fasteners for tightness. In particular, check the set screw in the wheel hub, bearings and the fan sheaves (pulleys). With power and gas to the heater OFF or prior to connecting ventilator to power, turn the fan wheel by hand to be sure it is not striking the inlet or any obstacles. Re-center if necessary.
Main Burner Adjustment Mod Valve Voltage Summary Volts DC Firing Mode 0 to 5 VDC Low Fire 5 to 15 VDC Modulation 15 to 20 VDC High Fire Manifold Pressure (in. w.c.) 1. Once the pilot has been properly established, the manifold gas pressure or temperature rise should be adjusted to jobsite conditions. The gas pressure regulator (integral to the combination gas control on size 1-3 heaters and located in the modulating valve on size 4-5 heaters) is adjusted at the factory for average gas conditions.
Heater Start Up Summary Is incoming gas pressure 7"-14"? (7"-5 psi. for size 4-5 units) No Adjust incoming gas pressure. Yes Adjust pilot flame. Setting incoming pressure: Presure must be measured at first "T" in supply gas line before the first gas valve. Adjusting the pilot: The pilot DC signal should be 12 VDC minimum. Lock unit into high fire. Does high fire produce No at least a 70°F temp rise and produce the Adjust high fire correct manifold pressure? Yes Lock unit into low fire.
Final Start Up Procedure 1. With the air and burner systems in full operation and all ducts attached, measure the system airflow. Motor sheave (pulley) is variable pitch, and allows for an increase or decrease of the fan RPM to adjust the airflow, as shown in the illustration below. For your convenience, a RPM chart is included in the following pages. 2. Once the proper airflow is achieved, measure and record the fan speed with a reliable tachometer.
Pulley Combination Chart Motor RPM 1725 1/3 to 1-1/2 HP MOTOR PULLEY AX BELTS 1VL34 Dd1 Dd2 Pd1 1.9 2.9 2 Pd2 3 Open BLOWER PULLEY AK114 TURNS ON MOTOR PULLEY PITCH DIAMETER 5 4 1/2 4 3 1/2 3 2 1/2 2 1 1/2 1 1/2 0 11 11.2 308 323 339 354 370 385 400 416 431 447 462 Dd1 Dd2 Pd1 Pd2 2.4 3.4 2.6 3.6 1/3 to 2 HP MOTOR PULLEY AX BELTS 1VL40 Open BLOWER PULLEY 10 - 20 IN.
Sequence of Operation The direct-fired heater is most easily understood when broken down into smaller individual systems. There are two main systems, a make-up air fan and a heater. The make-up air fan consists of a blower and motor. The heater may be further broken down into two control systems, the Flame Safety Control (FSC) and the Modulating Gas System (MGS). The burner mixes air with the gas (Natural or LP) which heats the air.
airflow switch to close. The high airflow switch protects against profile plate failures that cause excessive airflow through the burner. In the event that the pressure drop across the burner is not in the range of the airflow switch, gas flow to the burner is stopped by the Flame Safety Control. The graphs below illustrate the approximate cfm going through the unit vs. the differential pressure measured by the airflow switch.
FSC verifies proper Airflow Begins Pilot Trial For Ignition and turns on PTFI LED The pilot gas solenoid valve is opened, the spark igniter begins sparking, and the flamerod sensor watches for flame initiation When flame is established, the FLAME LED is illuminated and main valve opens and the FSC powers the modulating gas system system and gas flow begins modulating The FSC monitors the flame while the modulating system adjusts to the selected temperature The modulating system checks the disc
Components The following image and list outlines the typical direct fired heater components and their functions. 9 2 19 17 7 10 3 11 20 18 12 8 13 6 21 14 15 4 16 5 22 1 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. Gas Inlet – Main gas supply connection Motor Starter – Contactor with overload protection to start and protect motor. Cooling Interlock Relay (Optional) – Energizes power to cooling circuit on call for cooling.
Remote Panel Option The Remote Panel is a device used to control the operation of the heater from a remote location. This unit is available in a “2 Position” or “3 Position” configuration and with or without a cooling output. It also will accommodate both the discharge temperature dial and the Maxitrol space sensing Selectrastat. It is important to understand the following Remote Panel controls and uses: 3 1 4 2 FLAME FAILURE CLOGGED FILTER 1.
Troubleshooting The following tables list causes and corrective actions for possible problems with direct fired heater units. Review these lists prior to consulting manufacturer.
Burner Troubleshooting Chart Problem Pilot Does Not Light/Stay Lit Potential Cause Main gas if off Air in gas line Dirt in pilot orifice Gas pressure out of range Pilot valve is off Pilot orifice fitting leak Excessive drafts Safety device has cut power Dirty flame sensor Remote panel in “Vent” mode No spark at igniter Main Burner Does Not Light (Pilot is Lit) Defective valve Loose valve wiring Defective pilot sensor Shut off valve closed Defective flame safety controller Pilot fails as main gas valves o
Remote Panel Troubleshooting Chart Light Indication No Lights Condition Power not available to Remote Panel Proper Heating Operation Possible Cause Bad voltage to unit Main disconnect in “OFF” Position Circuit breaker tripped Bad main transformer No problem Manual/Off/Auto Switch in “Off” Position (3 Position Remote Panels Only) Improper damper function Low Temperature Thermostat Timed Out (Option) No Problem Manual/Off/Auto Switch in “Off” Position (2 Position Remote Panels Only) Heat/Vent Switch in “Ve
Troubleshooting Flowcharts Nothing Happens Is Overload tripped on starter? YES Reset & measure FLA of motor. Is it higher than rating? Adjust or change Pulley YES YES Is the air flow LED on Flame Saftey illuminated? Adjust or Replace Adjust pulley to achieve proper airflow.
MAINTENANCE To guarantee trouble free operation of this heater, the manufacturer suggests following these guidelines. Most problems associated with fan failures are directly related to poor service and maintenance. Please record any maintenance or service performed on this fan in the documentation section located at the end of this manual. WARNING: DO NOT ATTEMPT MAINTENANCE ON THE HEATER UNTIL THE ELECTRICAL SUPPLY HAS BEEN COMPLETELY DISCONNECTED AND THE MAIN GAS SUPPLY VALVE HAS BEEN TURNED OFF.
2 weeks after startup 1. Belt tension should be checked after the first 2 weeks of fan operation. Belts tend to stretch and settle into pulleys after an initial start-up sequence. Do not tension belts by changing the setting of the motor pulley, this will change the fan speed and may damage the motor. To retension belts, turn the power to the fan motor OFF. Loosen the fasteners that hold the blower scroll plate to the blower. Rotate the motor to the left or right to adjust the belt tension.
Start-Up and Maintenance Documentation START-UP AND MEASUREMENTS SHOULD BE PERFORMED AFTER THE SYSTEM HAS BEEN AIR BALANCED AND WITH THE HEAT ON (Warranty will be void without completion of this form) Job Information Job Name Address City State Zip Phone Number Fax Number Contact Purchase Date Service Company Address City State Zip Phone Number Fax Number Contact Start-Up Date Heater Information Refer to the start-up procedure in this manual to complete this section.
