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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 haz
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TABLE OF CONTENTS WARRANTY .................................................................................................................................................. 4 INSTALLATION ............................................................................................................................................. 5 Mechanical ................................................................................................................................................ 5 Site
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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. The equi
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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. Provide clearance around installat
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through vertical portion of the ventilator base Recommended Supply Ductwork Sizes assembly flange using a minimum of eight (8) lug Blower Size Duct Size Straight Duct Length screws, anchor bolts, or other suitable fasteners (not 10 14 x 14 48 in. furnished). Shims may be required depending upon 12 16 x 16 54 in. curb installation and roofing material. Check all 15 20 x 20 72 in. fasteners for tightness. The diagrams below show 18 24 x 24 86 in. different mechanical installation co
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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 blow
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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 o
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Electrical Before connecting power to the heater, read and understand this WARNING!! entire section of this document. As-built wiring diagrams are Disconnect power before furnished with each fan by the factory, and are attached to the installing or servicing fan. High door of the unit. voltage electrical input is needed for this equipment. This Electrical wiring and connections should be done in accordance work should be performed by a with local ordnances and the National Elect
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Remote Control Panel 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. The remote panel should be wired as shown below. Fire System Microswitch BK BK PR BK E 1 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
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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. Start Up Special Tools Required • AC Voltage Meter • Amperage Meter • Tachometer • Manometer • Standard Hand Tools
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Main Burner Adjustment 1. Once the pilot has been properly established, the Mod Valve Voltage Summary manifold gas pressure or temperature rise should be Volts DC Firing Mode adjusted to jobsite conditions. The gas pressure 0 to 5 VDC Low Fire regulator (integral to the combination gas control on size 5 to 15 VDC Modulation 1-3 heaters and located in the modulating valve on size 15 to 20 VDC High Fire 4-5 heaters) is adjusted at the factory for average gas conditions. It is importan
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Heater Start Up Summary Is incoming gas pressure Adjust No 7"-14"? incoming gas (7"-5 psi. for size 4-5 units) 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. Adjusting high fire: High fire manifold pressure should be 5" maximum for natural gas and 2.5" maximum for propane. High fire should produce
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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. Caution - Excessive speed will result
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Pulley Combination Chart Motor RPM 1725 1/3 to 1-1/2 HP MOTOR PULLEY Dd1 Dd2 Pd1 Pd2 AX BELTS 1VL34 1.9 2.9 2 3 Open TURNS ON MOTOR PULLEY Closed BLOWER PULLEY DATUM DIAMETER PITCH DIAMETER 5 4 1/2 4 3 1/2 3 2 1/2 2 1 1/2 1 1/2 0 AK114 11 11.2 308 323 339 354 370 385 400 416 431 447 462 1/3 to 2 HP MOTOR PULLEY Dd1 Dd2 Pd1 Pd2 AX BELTS 1VL40 2.4 3.4 2.6 3.6 Open TURNS ON MOTOR PULLEY Closed BLOWER PULLEY DATUM DIAMETER PITCH DIAMETER 5 4 1/2 4 3 1/2 3 2 1/2 2 1 1/2 1 1/2 0 AK114 11 11.2 400 416
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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. Flame Safety Control The first system to understand is t
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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. Simply measure the differential profile pressure drop at t
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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 Maxitrol system and gas flow begins modulating The FSC monitors the flame while the Maxitrol system adjusts to the selected temperature • The Maxitrol system checks the discharge air temperature (and the room
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Components The following image and list outlines the typical direct fired heater components and their functions. 8 10 2 18 20 11 3 12 19 21 4 13 9 14 15 22 6 7 16 5 5 6 17 23 1 1. Gas Inlet – Main gas supply connection 2. Motor Starter – Contactor with overload protection to start and protect motor. 3. Freeze-Stat Thermostat (Optional) – De-energizes blower motor if the discharge air temperature falls below the set point. 4. Cooling Interlock
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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 both a “2 Position” or “3 Position” configuration and with or without a cooling output. It also will accommodate both the Maxitrol 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. Manual/Off/Auto Switch -
