~... INS_TR_UC_TI_ON_P_AM_PH_LE_T _U-5_81_6 --~ GENERAL PURPOSE ELECTRONIC WHEEL DETECTOR INSTALLATION AND MAINTENANCE (UN ) CONTENTS ...

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1 WABCC... NS_TR_UC_T_ON_P_AM_PH_LE_T _U-5_81_6 -- GENERAL PURPOSE ELECTRONC WHEEL DETECTOR NSTALLATON AND MANTENANCE (UN ) CONTENTS General.... Operating Characteristics nstallation Procedure Maintenance Page /8 GENERAL The WABCO General Purpose Electronic Wheel Detector is a bi-directional rail-mounted device used for sensing the presence of railway car wheels. The unit has no moving parts and it is designed to detect car wheels passing over it at train speeds from 1-mph to 100-mph in all types of weather conditions. When activated by the presence of a car wheel. the detector will produce a square-wave pulse which will actuate other electronic equipment depending on the type of application. The General Purpose Electronic Wheel Detector can be economically used in conjunction with non-vital applications in classification yards. highway grade crossings; electric lock releases. car dumping equipment, A. C.. applications. activating rail oilers. and many other applications. PRNTED N U.S.A. AQ.67-SQQ UNON SWTCH & SGNAL DVSON. Westinghouse Air Brake Company PTTSBURGH, PA May

2 WABCD The detector is encased in casting compound that provides a hermetic seal to protect it from moisture, foreign particles, and to withstand shock and vibration. A condulet connector is provided to make wire connections. to the unit. The complete unit which is illustrated in Figure 1, is mounted to the web of the rail with two bolts. RAL WRE CONNECTONS MADE NSDE CONDULET i-----8"-----.i rr 3" ±1/16" 3/8 NCH BOLT (SDE VEW) UNDERGROUND CABLE ENTRANCE 3-5/16" (END VEW) Figure 1. General Purpose Electronic Wheel Detector OPERA TNG CHARACTERSTCS 1. Power Supply Requirements Voltage Current 9 to 15 volts D. C. - o. 25 amperes maximum during detection and with 70 ohm load. Source mpedance O. 5 ohm maximum (See "Operating Distance" below) Ripple - Less than O. 5 volts PK-PK Wires - 3 wires are required between detector and output location. Red wire (+) positive; black wire (-) minus; green wire output. 2. Output (Between green and black wire) Waveshape Pulse Duration - Square voltage pulse; rise time is approximately 4 microseconds. - Depends on speed of train millisecond minimum above 20 mph; 3000 milliseconds maximum below 20 mph. U-5816, p. 2

3 WABCC --"\ vi' 11.0!::; w > w... w C) <( 9.0 a.o!::; 0 > "- :::> 0 6.(} ,,,,.... i / i ,/ i..---,v :,..,""... /l' J / '/ i j f / i,...- V v i..--.j /., v V v ' i,...-- V,V /,,,, SUP PLY 15V DC 14V DC 1Jv 14v lv. lov DC DC DC DC 9V DC 4.0 NOTE - 70 OHMS S THE MNMUM LOAD ( LOWEST VALUE) / AT WHCH THE DETECTOR WLL FUNCTON PROPERLY. '! v LOAD (OHMS) Figure 2. Output Voltage vs. Load Resistance for Various Supply Voltages mpedance Level - Approximately 70 ohms - See Figure 2 for approximate output values 3. Train Speed The detector unit will detect wheels passing over it at train speeds from 1 mph up to 100 mph. 4. Operating Distance The operating distance between the detector and the power supply is subject to variation due to wire resistance and load. Figure 3, indicates the maximum distance for various loads and wire size which is based on cable capacitance of 100 picofarads per foot and 0. 5 ohm power supply impedance. Maximum recommended length is 2000 ft. U-5816, p. 3

4 WABCC. lax> J,_.,_. 2!:!!- ::t l(oo... 1'400 i: 1200 t ax>. ' , g g_ g ' / [/<:, v ),'' v v / j J '., J,," / J /" v / v /.. v ' / l/ v ' v v""", ' / L/ v v v,, v J [/, /,/...!..,,'... / J', v. le!,:5 'er (j Yo /, /,J " <:,«, v /,. <:,,,..,p,. c,t, NOTE - 70 OHMS S THE LOWEST OPERATNG LOAD PERMTTED LOAD RESSTANCE (OHMS) Figure 3. Maximum Length vs. Load Resistance for Various A WG Wire 5. Mounting The unit measures 3-3/8 inches wide by 3 inches high with an overall length of 13 inches and weighs approximately 5-1/2 pounds. t should be permanently bolted to the rail in accordance with mounting dimensions as illustrated in Figure 1. f mounted properly there will be adequate clearance and accurate detection for all car wheels meeting the A. A. R. specifications. (Car wheels for Class railroads should have a flange length of 1 iµch minimum to 1-9/16 inches maximum.) We recommend that the wheel detector unit and cable be protected from dragging equipment. An economical and practical method of protection is to fabricate a ramp type block of wood as illustrated in Figure 4 which can be mounted securely on top of the ties. This type of construction will deflect dragging equipment which might damage the detector unit. U-5816, p. 4

5 [' "" cri 00 O') 'P cri /8 --,- ' ':f'. L1 ':f'. 1-3(4 ':f'. J 12-1/4 17-1/4 l:j 17-1/4 L i J. 1 i L, 1 L.J [Jl -1 RAL A 140# R.E. 6-7/ R.E. 6-3/16 1J2il' R, E. 6-1/4 1311R,E. 6-1/4 115# R,E, 5-3/4 : : t : : 1 1, A } L J_ c Y tl /vy'./vtj lv\v\ t v, 11yA.1'1"v\',,.l ir -, 1r - 11 f --- ",,.... i'.. i : RAMP DETAL t (MADE FROM 7" x 911 OAK TE) 7/8 HOLE WTH 2 NCH L B l _ 11 RAL :-:-rr==r, -!,-GAGE LNE l.., Lr-,, --J,L J, i l vv1... J l J l,,,..., 11 v' t f.. ",!!"..,..,:"!,.!...,1 ',"," 1 1' 1 v \:v 1f '1 V.,,, 'f f r if ww' \! ', TOP VEW WHEEL DETECTOR AS SHOWN N FGURE 1. " :[[:", ' ' T r \ -,/ i: '-\i l! "-., j F _,,_, -:-:=====-==t-ral LJ F --=-1- -T- i: - - r--=- ::- _-: ---, L J L..J 91 L. _J SDE VEW C' BORE 1-1/8 DEEP FOR 3/4 DRVE SPKE GAGE LNE 1-7/8 1-3 (REF,) l r-i,: _1,1.1...,... -=-----, :::,_.Ji :;: _J L Figure 4. Typical Application of Protective Ramp for Wheel Detector B c 5-7/ /16 5-7/ /16 5-7/ /16 5-7/ /16 5-1/4 1-11/16 55/64 FOR 140# R, E. RAL 55/64 FOR 1331, 132#, & 131# R, E, RAL 7/8 FOR 115# R, E, RAL 6-15/16 FOR 140# R. E, RAL. 6-15/16 FOR 133#, 1321, & 1311 R, E, RAL { 6 5/8 FOR 115 H R, E, RAL

6 WABCC MPORTANT. The use of metal ramps are not recommended for this type of protection. The electronic components inside the detector are arranged for rail mounting and any additional metal surrounding the unit may affect its operation. 6. nterfacing When interfacing with other electronic equipment which requires the output to be clamped to a specific level, it is recommended that the following circuit be used on the input to the electronic equipment: TO WHEEL DETECTOR OUTPUT CRCUT 100'2.5 WATT GREEN WRE TO CLAMPNG l' CRCUT AND LOAD Q BLACK WRE NSTALLATON PROCEDURE 1. To apply the detector unit, (2) 3/8 inch holes are drilled through the web of the rail 3 inches (±1/16 inch) below the top of the rail and 5-1/2 inches (::1:: 1/16 inch) apart as illustrated in Figure The unit is then bolted to the inside of the rail. 3. Remove the cap from tp.e condulet which is held by two screws and pull out the free ends of the three flexible wires that lead to the detector unit. 4. Unscrew the cable grip from the condulet. Take the three open ends of the (twisted) underground cable going to the output location and insert them through the cable grip and into the condulet pulling them out through the large opening to make proper connections. Fasten the wire connectors to their respective ends with a standard crimping tool and join the connectors together (wires can be soldered if desired). NOTE.: The wire connectors (UJ706830) that are furnished can be applied to No. 14 or No. 18 gauge wires. 5. After proper wire connections have been made, fold the wires back into the condulet leaving a sufficient amount of slack inside the condulet connector and then replace the cap. Be sure rubber gasket is in place between the cap and condulet. Screw the cable grip back on to the condulet with firm pressure so that the cable appears to be snug within the condulet. U-5816, p. 6

7 WFBCC MPORTANT Allow plenty of slack in the cable above the ground for rail movement. The gauge of the underground cable required depends on the load resistance connected to the output and the distance between. the power supply and wheel detector. A No. 14 gauge, 3-conductor (twisted) underground cable is recommended for most applications which will handle any load above 300 ohms at a distance of 2000 ft. f other gauge cable is used refer to Figure 3. MPORTANT n applications where overhead line wire is used in addition to underground cable, between the detector and the output location, the equipment must be protected with lightning arresters. We recommend for surge protection, low voltage (WABCO style USG-UN314266).., lightning arresters which should be connected across the lines inside the housing at the output location and also at the detector location. At the detector lo.cation the arresters should be mounted inside the junction box used to connect the overhead line wires with the underground cable. A weatherproof box (WABCO UJ703152) is satisfactory for this purpose. MANTENANCE The General Purpose Electronic Wheel Detector requires very little maintenance. Keep the top of the detector clean to avoid accumulation of small particles of magnetic material that may affect its ability to detect car wheels. Periodically, a visual inspection is necessary to insure that the detector has not been damaged by dragging equipment. f trouble is experienced, check for faulty connections that may have developed. nsure that the Load Rating versus Wire Size and Length has not been exceeded. An indication of the problem mentioned above, is an occasional miss in detecting car wheels above 15 mph. A power supply that has developed a high output impedance will also cause similar problems and should be checked. U-5816, p. 7/8

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