feel that it is a step in the right directionthat bus people are payin - PDF document

1 feel that it is a step in the right dire
feel that it is a step in the right directionthat bus people are paying more attentionto tires in recent years. Tires deserve morecredit that most people give them, yet theyare often ignored. We all know we shouldcheck the air in our tires every morning buthow many of us really do that? Yet, tires areusually the single biggest reason for busespulled over at the side of the road. Moreover,with the increasing price of fuel, keeping yourtires properly inßated can make a signiÞcantdifference in fuel economy. opments in the area of bus tires is the avail-ability of tire monitoring systems. There arenow several different systems on the mar-results, most will monitor both tire pressureand tire temperature. This provides the dri-ver with a warning of a tire blow out so thatthe driver know when tire pressure is lowor tire temperature is high so that action canbe taken before a major problem occurs.Prevost introduced the Beru tire monitor-The system was developed by Beru, a spe-cialized German manufacturer, and has beenBMW, Porsche and Lambroghini. At this pointthe Beru system is not an aftermarket prod-the new coach as it is built. While the Beru sys-market, our research suggests that it is prob-of the tire monitoring systems we have seen. Like all of these tire monitoring systems,the Beru system starts with a sensor and National Bus Trader / October, 2008 vost seated coaches, the Beru Tire Monitoring System is probably the most sophisticated and most useful of the tire monitoring The Beru Tire Monitoring Systemfrom Prevostby Larry PlachnoPhotos courtesy of Prevost transmitter. Some of the simpler systemsuse external sensors that screw on to thevalve stems. The SmarTire sensor isband. Beru uses a high strength potted plas-tic casing that is screwed to the valve insidethe wheel. The special screws that are usedfor this are powder-coated and can only beThere are typically nine sensors providedper coach: two for the steering tires, four forthe drive tires and two for the tag/bogietires. The ninth sensor/transmitter goes onyour spare tire. There is an alternate seven-width drive tires.some other tire monitoring systems. Thereare three antennas to pick up the radio sig-nals from the tires. As you might expect,the three axles of the coach. Wires run fromthe antennas to an electronic control mod-ule that effectively controls the system. This,in turn, is wired into a display on the dashwhen tires are changed, information has tobe entered so that the electronic control mod-ule knows which sensor is in which tire posi-tion. At that same time, there are also someparameters that must be entered to

2 get opti-What makes the Beru system so
get opti-What makes the Beru system so special?In my opinion, there are several key factorsthat set it apart from other tire monitoringmakes it more modern and reliable thansome of the other systems that still use ana-A second factor that makes a big differ-ence, is that the Beru system samples thetire pressure and temperature every minuteregardless of whether you are parked ordriving. Some of the other tire monitoringsystems sample considerably less fre-quently. One popular system samples thetire only once every 15 minutes whenparked and every three to four minuteswhen moving. Hence, this frequent sam-pling gives the Beru system two majormuch sooner if you have a problem. Thesecond advantage is that you can get a pre-trip tire pressure reading a minute afterstarting your engine Ð before your air is upand before you drive off.The third factor that impressed me is theeasy-to-read dash display for the driver. Thisalso provides an alarm system, lets you mod-ify your parameters within reason, and evenlets you select your preferred language andunits of measure.Pre-Trip Check and ParametersOne of the reasons why I like the Berusystem is its marvelously easy-to-read dis-play. The top part of the display has a sim-ple diagram of your axles and tires: two ontwo on the third axle. Displayed next to eachwheel/tire is the pressure or temperature ofthat particular tire. Your spare tire is alsoshown below the third axle. In the event thatthe system does not have a reading from aparticular tire, it shows two dashes (Ð Ð). Thebottom part of the display shows warningWhen you Þrst turn your coach on, theBeru Tire Monitoring System display comes National Bus Trader / October, 2008 Here are some of the standard components used on the Beru Tire Monitoring System. At the upperthe Tire Pressure Monitoring System Receiver. At the upper right is the Tire Pressure Monitoring This photo shows the Beru Tire Monitoring System display mounted on this Prevost bus dash ondriver. to life and goes into its Pre-Trip Check. Ini-tially, the nine tires are shown with dashessince there are no readings. When the sys-tem gets information from each of the sen-sor/transmitters as they Òreport in,Ó thedashes are replaced by numbers. Since theyreport in every minute, you should have acomplete tire check before your air pressureIn normal pressure deviation mode, thesystem shows positive and negative num-bers to indicate how many pounds of pres-sure each tire varies from the pre-set targetpressures. There is also a gauge pressuremode that displays the actual tire pressures.Beru system is that your driver gets anaccurate re

3 ading of all tires a minute afterstartin
ading of all tires a minute afterstarting the coachÐwithout having towalk around the coach with a tire gauge,and regardless of the weather. If one tirereads low or high, he can take appropriateThere are several options and parame-ters that should be set before you use thesystem. They can be changed from time towhether you want tire temperatures shownin fahrenheit (¼F) or celsius (¼C). Do youwant messages in English or French? Youcan also control your backlight and contrastYou must also set target pressures foryour tires. This is the cold tire pressure youwant for each wheel position. The ÒPres-sure DeviationsÓ screen will show poundsper square inch above or below this num-ber. The factory sets recommended pres-sures but the system can be set as much as30 percent higher or 20 percent lower to suitsonal differences, unusual loads, or just per-sonal preference.You also are given an opportunity toin pounds per square inch from your targetpressures should generate an alarm? Whattire temperature should generate a high tem-perature alarm? Do you want a audiblean alarm? You even have the option of hear-ing a sound when you press keys on thedash display.remaining on your sensor batteries. Thebattery life display generates numbers from100 down to 1 showing percentage of bat-tery life remaining. This gives you amplewarning when you will need to replace abattery.When doing the pre-trip inspection, if allthe tires are within limits on pressure youwill get a ÒTire Pressures: OKÓ display. Ifthere is a problem, the system will generatefour basic alarms; two are considered non-critical while two are considered critical. Ittem generates an alarm, it places a blinkingrectangle around the offending pressure ortemperature so the driver can spot it imme-diately without having to take his eyes offthe road to search the display.One non-critical alarm is ÒSystem Error,not all tires monitored.Ó This indicates thatthe system has failed to receive a readingfrom one or more tires. Figures for themissing tire are shown as two dashes insideof a blinking rectangle. The second non- National Bus Trader / October, 2008 One of the major advantages of the Beru Tire Monitoring System is that the driver can monitor allto walk around the coach with a tire gauge to check the tires. This photo of a Prevost ÒHÓseries The easy-to-read display is a major feature of the Beru Tire Monitoring System. The illustration critical alarm is ÒPressures Not Optimal,Readjust at Next Stop.Ó A blinking rectan-gle will appear around the offending tirepressure. This means that the pressure onone tire has deviated far enough from thetarge

4 t number to generate an alarm. How-ever,
t number to generate an alarm. How-ever, the deviation is small enough so thatstop. With the non-critical alarms, the dri-acknowledge the warning and stop the rec-tangle from blinking.There are two critical alarms. One isÒStop, Flat Tire.Ó This alarm is generatedwhen a tireÕs pressure falls substantiallybelow the target pressure. The second criti-cal alarm is: ÒStop, High Temperature.Ó Asyou have already guessed, this alarm indi-cates that one of your tires has exceeded yourtemperature alarm temperature. The blink-ing rectangle will continue blinking until theerror condition disappears, even if you toucha key.In normal operation while driving, theBeru display shows the ÒPressure Devia-tionÓ screen where each tireÕs pressure isabove or below your target settings. This ispressing a key, the driver can view actualpressures or actual temperatures. Watch-ing temperatures occasionally could let thedriver know about a potential heat prob-lem from bearings or brakes. In the eventthat an alarm is triggered, the alarm word-while a blinking rectangle appears aroundthe offending Þgure. In the event of a ÒStop,High TemperatureÓ alarm, the displayfigures will change from pressure totemperature.There are several advantages of the BeruTire Monitoring System including the¥It will help improve coach safety bypreventing heat buildup due to underinßa-tion, a leading cause of blowouts and tread¥Keeping tire pressures at optimum lev-reduce wear, which extends tire life.¥Since tire failure is a main cause ofvehicle breakdowns, this system willincrease coach uptime, keeping your coachon the road.¥It lets drivers and mechanics knowwhat tire pressures are desired. There are four particular advantages thatI feel are very noteworthy. One is that the Berusystem saves the time and effort of checkingtire pressures manually yet warns the driverabout a tire problem before he leaves the yardtire problem early enough so that he can takeaction and thus prevent it from turning intoa major problem or an out-of-service bus withpassengers at the side of the road.The third advantage is that you get accu-rate tire readings without the necessity ofkneeling in mud or gravel with your airing tire pressures manually can often causeproblems with valves sticking and failing toclose properly. With the Beru system, thepressure is sampled without the need to acti-vate the valve or use a tire gauge.Additional information on the Beru TireMonitoring System is available from yourPrevost representative. National Bus Trader / October, 2008 The Beru Tire Moni-toring System offersowner. It watches fortaken in the Tampa 9698 W. Judson R