Wiring Diagram for Cessna 195

sections covering combustion heaters. These aircraft manuals are to be used rather than this manual. 1 Section I 2 JANITROL TABLE SHOWN BELOW LISTS THE HEATER ASSEMBLIES FOR EACH MODEL SERIES. Part No. 96C60 Part No. MODEL B1500 HEATERS Part No. 99C42 MODEL B2030 HEATERS Part No. Part No. 96C92 15D23 15D83 15D94 20D35 20D35-1 21D66 22D01 37D88 A37D88 B37D88 42D79 56D03 74D01-1 74D01-2 74D01-3 * indicates kerosene fuel burning heater assemblies MODEL B3040 HEATERS Part No. 82D31-1 82D31-2 Part No. 96C62 Part No. A39D59 96C62-1 B39D59 62D95-1 63D98 15D31 C39D59 63D98-1 15D96 D39D59 82D20-1 22D25 39D84 82D20-2 22D25-1 41D95 88D81-1 32D99 45D70 88D81-2 * 34D35 45D70-1 88D81-3 * A34D35 34D51 A34D51 45D70-2 90D38-1 47D65 90D38-2 47D65-1 96D75-1 B34D51 C34D51 D34D51 37D77 37D77-1 39D59 47D65-3 04D34-1 * 56D86 04D34-2 * 62D33 * 10E21-1 * 62D33-1 * 10E21-2 * 62D33-2 * 62D95 10E21-3 * 10E21-4 11E82-1 * indicates kerosene fuel burning heater assemblies MODEL B4050 HEATERS Part No. Part No. Part No. 99C80 65D79-2 07E94-1 99C80-1 65D79-3 07E94-2 15D48 81D94-1 08D36-1 15D87 81D94-2 09D21-1 15D98 81D94-3 13E55-1 39D90 82D01-1 13E55-2 39D90-1 02E17-1 19E69-1 65D79 02E17-2 23E63-1 65D79-1 07E02-1 24E07-1 * indicates kerosene fuel burning heater assemblies JANITROL SECTION II DESCRIPTION AND OPERATION 2.1 Description of Heater and Basic Components Janitrol Business and Utility Aircraft Heaters embody the same proven reliability as Janitrol heaters, used in the majority of Commercial, Military, and Private transport aircraft for over 38 years. A few of the outstanding features on these heaters are as follows: Spark-Spray Ignition The controlled atomized spray from a specially designed spray nozzle, coupled with high-voltage spark plug ignition, insures instant firing and continuous burning under all flight conditions. Spark-spray ignition combined with the exclusive Janitrol whirling-flame combustion has been proved by million of hours of heater operation in all types of aircraft throughout the world. Heat is produced by buming a fuel-air mixture in the combustion chamber of the heater. Aviation fuel is injected into the combustion chamber through the spray nozzle. The resulting cone-shaped fuel spray mixes with com- bustion air and is ignited by a spark from the spark plug. Electric current for ignition is supplied by an ignition unit which converts 12 volts or 24 volts to high-voltage, oscillating current to provide a continuous spark across the spark gap. A shielded, high voltage lead connects the ignition assembly to the spark plug. Combustion air enters the combustion chamber tangent to its surface and imparts a whirling or spinning action to the air. This produces a whirling flame that is stable and sustains combustion under the most adverse conditions because it is whirled around itself many times. Therefore, ignition is continuous and the combustion process is self-piloting. The burning gases travel the length of the combustion tube, flow around the outside of the inner tube, pass through cross-over passages into an outer radiating area, then travel the length of this surface and out the exhaust. Ventilating air passes through the heater between the jacket and combustion tube assembly outer surface and through an inner passage in the assembly. Consequently ventilating air comes into contact with two or more heated, cylindrical surfaces. THE ELECTRIC FUEL PUMP (Aviation Gasoline Applications) (See Figure 2-2) For aviation gasoline applications, the electric fuel pump provides fuel at 7.0 psi for ground operation and during flight. (The heater may be operated from the engine fuel pump, provided the fuel pressure output is controlled with- in the operating pressure range of the heater). a. Two (2) fuel pumps working in series can be used where the 7 psi pump is not able to provide sufficient fuel pressure. Kerosene Fuel Applications (See Figure 2-3). The electric fuel pump assembly is ideally suited to use, when needed, in aircraft heater fuel systems to provide proper pressures from fuel source, through a fuel control HEATED AIR EXHAUST GASES HIGH VELOCITY WHIRLING FLAME SPARK PLUG COMBUSTION AIR INLET FUEL INLET SOLENOID VALVE FRESH AIR FROM BLOWER FIGURE 2-1 Diagramatic Cutaway of Heater to Show Whirling Flame Action 3 Section II JANITROL adapter section (between motor and pump) so as to drain fuel in the event of pump seal leakage. Close the remaining drain openings using MS20913-IS plugs. The drain should always be on the bottom, connecting to 1/4" tubing that extends through bottom of aircraft, clearing outer "skin" or any other part of the aircraft. It should be scarfed at an angle approximately 30° to the direction of flight so as to create a negative pressure on the end of the drain. A fuel pressure relief valve must be used whenever this pump is part of installation. Fuel connections are all standard pipe threaded. THE PRESSURE RELIEF VALVE FIGURE 2-2 Electrical Fuel Pump - Aviation Gasoline system to heater fuel nozzle. Pump supply is adequate for use with all kerosene burning heaters in the Janitrol Aero's line and can be mounted in a horizontal position, or verti- cally mounted provided the motor end of pump is at the top. Installation note: regardless of mounting position, an appropriate drain connection should be selected in the 019 FIGURE 24 The Pressure Relief Valve The relief valve is used, as its name implies, for relieving excessive pressure build-up in the heater fuel system. It must be used whenever kerosene fuel is used in an installa- tion. It can be adjusted after installation in the system if a pressure gauge is temporarily installed on the outlet or regulated side of the fuel pump. Fuel Regulator and Shutoff Valve (See Figure 2-5) Refer to Janitrol Instruction Part No. 56D67 This unit provides preset, regulated fuel pressure as well as remote shutoff to the heater, regardless of fuel inlet pressure variations. It is available in 1.0, 7.5 and 12.0 psi settings depending upon installation requirements, with inlet pressures up to 50 psi. The shutoff valve is operated by a solenoid. FIGURE 2-3 Electric Fuel Pumps used with Aviation Kerosene Fuel Applications. 4 FIGURE 2-5 The Fuel Regulator and Shutoff Valve JANITROL Section II Duct Switch (See Figures 2-6-1 and 2-6-2) This switch is installed in the ventilating air duct down- stream from the heater to sense the ventilating air outlet temperature. To select the desired cabin temperature, the switch may be adjusted manually from a high of 250°+ 10° downward through a range of 146°. Duct switches are also set at 195 to 225°F. The switch has a differential of 15° ± 5° at any given setting. Ventilating Air Blower (See Figure 2-7) This blower is attached to the inlet end of the heater assembly and provides a source of ventilating air through the heater. Ram air from the ventilating air intake scoop is normally used during flight. The blower can run con- tinuously unless some provision is made to de-energize it during flight and use ram air exclusively. The hot line should be the circuit interrupted by a switch, not the line from blower to ground. 1. Control lever 3. Switch cover 2. Setscrew 4. Adjustable duct switch FIGURE 2-6-1 Duct Switch Assembly SET SCREW (TYPICAL) HIGH LIMIT POSITION "H" 15° H ·CONTROL WIRE 130° 2 LOW LIMIT POSITION "L" FIGURE 2-6-2 Top view of Duct Switch showing typical control lever positions. FIGURE 2-7 Vent Air Blower Assembly Combustion Air Blower (See Figure 2-8-1, 2-8-2 and 2-8-3) This centrifugal-type blower is mounted separately from the heater to permit more flexibility to installation and supplies combustion air to the combustion chamber of the heater. Performance of the combustion air blower is assisted by the use of ram air during flight. FIGURE 2-8-1 The Combustion Air Blower Assembly 5 6 Section II o 00 FIGURE 2-8-2 Combustion Air Blower FIGURE 2-8-3 Combustion Air Blower and Regulator Assembly 2.2 JANITROL Operating Controls (See Figure 2-9) The schematic diagram (Figure 2.9) shows in addition to the heater circuit, a suggested customer control circuit. For the purpose of this manual, this circuit will be used to describe heater operation. However, the customer control circuit can and will vary in different installations. a. The "Master Switch" is connected in the line that supplies electrical power to all heater equipment and controls. When this switch is in the "OFF" position, the entire heater system is inoperative. This switch can have a (vent) position which permits use of the ventilating air blower to circulate cool air through the system for summer ground operation. With the switch in "VENT" position, the heater is inoperative, and only the ventilating air blower is energized. b. The "HEATER START SWITCH" is a normally open, momentary "ON" switch that supplies power 05151A ॐ JANITROL C. 2.3 a. b. to (lock-in) the safety relay through which power is supplied to the ignition and fuel circuits of the heater. The "HEATER STOP SWITCH" is a normally closed, momentary "OFF" switch that de-energizes or breaks the (lock-in) power to the safety relay to stop the heater fuel supply and ignition. Operating Procedure (See Figure 2-9) Place the "MASTER SWITCH" in the "ON" (or "HEAT") position. The ventilating air and com- bustion air blowers should operate and the red "HEATER FAILURE LIGHT" should be on. Energize then release the HEATER START SWITCH. The red HEATER FAILURE LIGHT should de- energize (go out), and the green "HEATER RUN- NING LIGHT" should energize (light). The heater will ignite and continue to operate. A short time lag may be required for the fuel pump to purge the fuel lines of air bubbles. This time lag should not be more C. d. e. Section II than ten seconds except in cases where the fuel line has been drained due to maintenance overhaul being performed. The "DUCT SWITCH" can be set to regulate the cabin temperature for desired comfort level. If this switch is set for ground operating comfort, it may be necessary to reposition it, since ram air will increase the ventilating air flow and the heater output. To stop heater operation, push, then release the "HEATER STOP SWITCH." The heater will de- energize and the red "HEATER FAILURE LIGHT" will then energize. The green "HEATER RUNNING LIGHT" will be de-energized. The blowers should be allowed to operate for several minutes to cool and purge the heater after operation. To stop blower operation, de-energize or tum "OFF" the "MASTER SWITCH." TERMINAL 1 STRIP CIRCUIT BREAKER MASTER SWITCH LANDING GEAR SWITCH 12 OR 24 VOLTS D.C. RADIO NOISE FILTER HEATER START SWITCH MOMENTARY "ON" COMBUSTION AIR BLOWER ADJUSTABLE DUCT SWITCH HEATER STOP SWITCH MOMENTARY, "OFF" HEATER FAILURE LIGHT (RED) LOCKOUT RELAY OPOT HEATER RUNNING LIGHT (GREEN) AIRCRAFT CONTROL CIRCUIT - OPTIONAL FIGURE 2-9 Wiring Diagram (typical) 106-10 301-16 Hour Meter 201-16 FUEL PUMP AND/OR SHUTOFF VALVE 203-16 104-18 103-16 101-18 OVERHEAT SWITCH (N.C.) 302-16 RADIO NOISE FILTER VENT. AIR BLOWER COMS. AIR PRESSURE SWITCH 102-16 CYCLING SWITCH (N.C.) 202-16 RADIO NOISE FILTER 105-16 IGNITION UNIT FUEL SOLENOID VALVE SPARK PLUG 7 JANITROL SECTION MAINTENANCE SERVICE Instructions contained in this section apply to Business and Utility Aircraft heaters covered in this manual. They consist of periodic inspection, adjustments, and minor corrections required at normal designated intervals for the purpose of maintaining the heating system in peak operating condition. These inspections assume that a heating system includes accessory components mentioned in preceding paragraphs. 3.1 a. b. Preflight and/or Daily Inspection Inspect the ventilating air inlet scoop, combustion air inlet scoop, exhaust outlet and fuel drain for possible obstructions. Make sure that all of these openings are clear of any restrictions and that no damage has occured to air scoop protrusions. During preflight inspections look in the area of the combustion heater exhaust tube for large or unusual accumulations of soot on the skin of the aircraft. Soot accumulates are caused by the heater burning at a fuel "rich" condition. Incorrect fuel pressure to the heater, a restriction in the combustion air inlet line, a loss of performance by the combustion air blower, or partially clogged fuel nozzle are all causes of this condition and corrective maintenance should be performed. Perform an operational check as follows: 3. b. C. d. e. f. h. 8. 3.2 3. Place the "MASTER SWITCH" in the "ON" (or "HEAT") position. The ventilating air blower and combustion air blower should op- erate and the red "HEATER FAILURE LIGHT" should be energized. b. C. Operate both the combustion air blower and ventilating air blower and check each for un- usual current draw, noise or vibrations. Refer to Table II for trouble shooting and for recom- mended maintenance. To proceed with the operational check, follow Paragraph 2.3 entitled "Operating Procedure", Steps A through E. This procedure should be repeated one or more times. 3.3 100 Hour Inspection* The mandatory 100-Hour Inspection shall be conducted on new heaters or overhauled heaters with a new combustion tube assembly upon the accumulation of 500-heater hours or twenty- four (24) months, whichever occurs first, and thereafter at in- tervals not to exceed 100-heater hours or twenty-four (24) months, whichever occurs first. If a timing meter is used on. the heater assembly, it should be connected across terminals Numbers 2 and 5 on the heater terminal strip. If a timing meter is not used count one (1) heater hour for each two (2) flight hours for normal aircraft operation. Consideration should be given for any excessive ground operation of the heating system. The 100-Hour Inspection consists of the functional checks/in- spections as listed below and the Pressure Decay Test. *NOTE: The term hours in this manual refers to heater hours Inspect ventilating air and combustion air inlets and exhaust outlet for restrictions and security at the air- craft skin line. If external scoops, jutting out into the air stream are used, make sure they are not distorted and are securely attached to the aircraft skin. Inspect the drain line to make sure it is free of ob- structions. Run a wire through it if necessary to clear an obstruction. Check all fuel lines for security at joints and shrouds, making sure that no evidence of leaks exists. Also check for security of attachment of fuel lines at the various attaching points in the aircraft. Inspect electrical wiring at the heater terminal block and components for loose connections, possible chaf- fing of insulation, and security of attachment points. Inspect the high voltage cable connection at the spark plug to make sure it is right. Also, examine the cable sheath for any possible indications of arcing, which would be evidenced by burning or discoloration of the sheath. Inspect the combustion air blower assembly for secu- rity of mounting, security of connecting tubing and wiring. Tighten any loose electrical terminals and air tube connections. Operate both the combustion air blower and ventila- ting air blower and check for unusual noise or vibra- tions. Refer to Table II for recommended maintenance. It is recommended that the condition of the spark plug be checked for operation as described in Para- graph 3.8. Following the 100 hour inspection, perform the pre- flight operating check as described in Paragraph 3.1. NOTE Due to certain flight patterns, the sensing tube from the pressure switch to heater exhaust may be clogged. Disconnect at switch and clear tube by blowing air through it. If combustion product residue has col lected in the exhaust end of the tube, it may be necessary to clear the sensing tube with a wire. 3.3.1 Pressure Decay Test Setup Evaluation of the condition of the combustion chamber shall be made at the 100 hour inspection. This test is in- tended to be accomplished while the heater is installed with a minimum of accessory disconnection. When necessary or desired for convenience. the heater assembly may be removed from the aircraft to conduct the pressure decay test. The following equipment is necessary to conduct the Pres- sure Decay Inspection Test. 1. 2. 3. Pressure Decay Test Kit, Part No. 26E24-1. 1/4-inch air supply line with 0-10 PSIG pressure gage, shutoff valve and air pressure regulator. (B). See Figure 3-1. 1/4-inch air supply line with 0-100 PSIG pressure gage, shutoff valve and air pressure regulator. (A). See Figure 3-1. 00 JANITROL To conduct the pressure decay test, the heater must first be sealed at all openings into the combustion chamber assembly. The openings into the combustion chamber include the com- bustion air inlet tube, combustion air pressure switch differ- ential sensing lines, fuel drain, and the exhaust tube. (See Figure 3-1) Loosen and remove all flex tubing, elbows and adapter, that may be mounted between the combustion air blower and the heater. NOTE The Combustion Air Pressure Switch must not be pressurized during the pressure decay test. The remaining steps necessary to prepare for the pressure decay test are listed in paragraphs 3.3.2 thru 3.3.9. 3.3.2 If the Combustion Air Pressure Switch is mounted directly on the heater, loosen the Combustion Air sensing lines from the Combustion Air Pressure Switch. Identify and then loosen two (2) wires from the Combustion Air Pressure Switch. Remove the Combustion Air Pressure Switch from heater by unscrewing the switch from the fitting. 3.3.3 To obtain access to the heater exhaust tube in some aircraft, you must loosen and remove aircraft mounted exhaust tube and exhaust tube shroud from the heater assembly. Then insert exhaust seal bulb. Section III and obtain access to the heater mounted exhaust tube. 3.3.4 Install pressure seals on Combustion Chamber using the parts supplied in the Combustion Chamber Pres- sure Decay Test Kit (Part No. 26E24-1) (See Figure 3-2). The following attachments are to be made on the heater. Install and tighten in place (as shown on Figure 3-3) the Combustion Air Tube Pressure Supply Assembly (Part No. 26E26-1) using the hose clamps (Part No. 26E25-1). Attach 1/4-inch supply line as shown in Figure 3-1. or 3-5. Install and tighten cap (Part No. 11E97-1) on fitting where combustion air pressure switch was mounted. (See Figure 3-2 and 3-3) 3.3.5 Loosen the overboard drain line from the heater and install a pipe cap (Part No. 11E97-2) if the drain fitting is equipped with a 1/4-inch pipe thread or install a pipe plug (Part No. AN933-1) if the drain fitting has a 1/8-inch in- ternal pipe thread. Alternate method is to seal drain line at air- craft skin. Note that Heater Part Number 81D94 is equipped with two (2) drains. Both drains must be capped. NOTE: Check all lines and fittings for leakage prior to starting pressure decay test. Heater Assembly Ventilating Air Outlet 0 to 10 PSIG Pressure Gage Shutoff Valve Inlet Fitting PN 26E26-1 and PN 26E25-1 ¼" Supply Line Air Supply (B) Air Pressure Regulator (B) Ventilating Air Inlet Exhaust Seal Tube Installed & Inflated Tube Extention PN 26E27-1 to be used if heater is equipped with long exhaust tube. See kit Drawing. Figure 3.2 Shuttoff Valve 1/8 or 3/16" Sensing Line Reducer PN AN919-2 or (X)E24-1 1/4-Inch Supply Line Plug Drains PN AN933-1. 11E97-1 or 90E25-1 0 to 100 PSIC Gage Air Pressure Alternate method* Drain may be sealed at aircraft skin line. (User to supply seal) Air Supply (A) for inflating seal bulb Regulator (A) for inflating seal bulb. *NOTE: If alternate method of sealing drain line is used, a check must be made to see if any leakage occurs at the fitting between the drain line and the heater drain boss. FIGURE 3-1 Test Set-Up Pressure Decay Inspection Test Section III 10A) 9A 2 3 Clamp PN 98C27-10 Reference 10 JANITROL 7 0 ITEM NO. PART NUMBER DESCRIPTION -1 98C27-2 - Clamp Hose, Worm Drive & is too is is -8 4 26E26-1 11E97-1 90E25-1 90E24-1 26E27-1 -9 26E29-2 .9 A 90E06-2 Seal Bulb, 2-inch (1 extra supplied) -10 26E29-1 Seal Assy Exhaust Tubes - 1 1/2-inch Nominal Diameter -10A 90E06-1 .11 28E87-1 Seal Bulb, 1 1/2-inch (1 extra supplied) Instruction Sheet 11E97-2 MS24399-3 Combustion Air Tube - Pressure Supply Assembly Cap 1/8-inch Pipe Threads - Combustion Switch Fitting - Plug-Hex, 1/8-inch Pipe Thread - Drain Plug Cap 1/4-inch Pipe Thread For Drains with 1/4-inch Exterior - _ Reducer 1/4-inch Tube to 3/16-inch Tube Union 3/16-inch Tube Tube Assy Extension - 3/16-inch Diameter For Item -7, -9, and/or -10 Seal Assy Exhaust Tubes - 2-inch Nominal Diameter 10 FIGURE 3-2 Combustion Tube Pressure Decay Test Parts Kit (Part No. 26E24-1) JANITROL FIGURE 3-3 Tighten Hose Clamp (Part No. 98C27-2) after assembly installed over combustion air inlet tube. Inlet Fitting Assembly Part No. 26E26-1 Inspect inlet tube to be sure all holes are covered with hose or are plugged. Fitting MS 33656 for use with 1/4 in. supply line. Section III Thread Size 7/16-20 UNJF-3A Install Rubber tube over combustion air inlet tube. Slide rubber tube onto combustion inlet tube as far as possible. Install cap (Part No. 11E97-1) on Combustion Air Pressure Switch Fitting Combustion Air Pressure Switch Fitting Combustion Air Inlet Tube Typical Heater Jacket Configuration _ Combustion Air Tube Pressure Supply Assembly Installed 11 Section III Exhaust Tube Shroud Heater Jacket Configuration Pressure Decay Inspection Test Section Thru Typical Combustion Heater Showing Location of Exhaust Tube Seal JANITROL Outer Combustion Tube of Heater Seal Configuration when Pressurized 3/16" or 1/8" Dia. Sensing Line Note: DO NOT BEND OR DISTORT SENSING LINE INSIDE EXHAUST TUBE. Use eye goggles or mirror and flashlight to check position of inflated seal bulb in exhaust tube. Repositioning of seal bulb in exhaust tube may be required to achieve leaktight seal. Remove pressure from both systems (A) and (B) before attempting to reposition seal in exhaust tube. FIGURE 3-4 Exhaust Tube Seal Shown Installed Just Prior to Inflation 12 Exhaust Seal Tube Part No. 26E29-2 or 26E29-1