{"id":7920,"date":"2013-09-10T12:23:30","date_gmt":"2013-09-10T11:23:30","guid":{"rendered":"https:\/\/mag.ebmpapst.com\/en\/?p=7920"},"modified":"2024-03-12T17:57:18","modified_gmt":"2024-03-12T16:57:18","slug":"integrated-diagnostic-system-for-fans","status":"publish","type":"post","link":"https:\/\/mag.ebmpapst.com\/en\/industries\/electronics\/integrated-diagnostic-system-for-fans_7920\/","title":{"rendered":"Inte\u00adgrated diag\u00adnostic system for fans"},"content":{"rendered":"

The life span calcu\u00adla\u00adtion gener\u00adally applied to fans today is based on the assump\u00adtion of statis\u00adtical aver\u00adages. For this, there are various calcu\u00adla\u00adtion formulas and eval\u00adu\u00ada\u00adtion criteria for loads such as temper\u00ada\u00adture, speed or dust and humidity. If oper\u00adating condi\u00adtions greatly deviate from the norm, this approach cannot provide any mean\u00adingful values for the actual service life of an indi\u00advidual on-site fan. In order to achieve a more reli\u00adable state\u00adment about the actual service life poten\u00adtial here as well, in addi\u00adtion to general labo\u00adra\u00adtory find\u00adings, the actual on-site loads have to be measured during oper\u00ada\u00adtion, added up and included in the calcu\u00adla\u00adtion. A new diag\u00adnostic tool for fans collects the rele\u00advant data for this and calcu\u00adlates the indi\u00advidual remaining service life under the actual oper\u00adating condi\u00adtions. Thus oper\u00ada\u00adtion and main\u00adte\u00adnance of diffi\u00adcult-to-reach fans are deci\u00adsively improved and the reli\u00ada\u00adbility of the overall system increases.<\/p>\n

Statis\u00adtical state\u00adments are only as good as permitted by the assumed input data. Even the best calcu\u00adla\u00adtion program is not able to provide any real\u00adistic state\u00adment about the service life of a product if the assump\u00adtions are incor\u00adrect. However, precisely with fans for exposed appli\u00adca\u00adtions in a safety area or for systems that are diffi\u00adcult to access, such as cellular tele\u00adphone stations on moun\u00adtains, the most exact possible deter\u00admi\u00adna\u00adtion of (remaining) service life is impor\u00adtant to the oper\u00ada\u00adtors. There\u00adfore it is ideal if the calcu\u00adla\u00adtion includes the actual load of the indi\u00advidual fan where it is used. If this takes place right in the fan, and if the fan can issue an alarm signal when a config\u00adurable safety threshold is exceeded, that improves the reli\u00ada\u00adbility of the overall system. There\u00adfore there is no need for any cost-inten\u00adsive preven\u00adtive replace\u00adments; that saves time, money and personnel.<\/p>\n

Existing eval\u00adu\u00ada\u00adtion method<\/h2>\n
\"Bild1_Dauerlaufraum\"<\/a>

Figure 1: In the endurance test room \u2013 the data for the conven\u00adtional life span calcu\u00adla\u00adtion is acquired using the climate chamber.<\/p><\/div><\/div>\n

Existing, conser\u00adv\u00ada\u00adtive cata\u00adlogue infor\u00adma\u00adtion regarding service life refers to an accepted, average oper\u00adating point; for example, service life L10 of 70,000 hours at 40\u00b0C ambient temper\u00ada\u00adture and 3,600 revo\u00adlu\u00adtions per minute. There\u00adfore they are more of a stan\u00addard value for the prac\u00adtical eval\u00adu\u00ada\u00adtion, since oper\u00adating temper\u00ada\u00adture and speed contin\u00adu\u00adously change throughout the day and over the seasons, thereby affecting the service life. To this are added unfore\u00adsee\u00adable factors, such as dust or humidity, which are taken into account only in special cases in the labo\u00adra\u00adtory. Usually, current eval\u00adu\u00ada\u00adtions of life\u00adtime are based on labo\u00adra\u00adtory testing with defined stan\u00addard condi\u00adtions for temper\u00ada\u00adture and speed (Figure 1).<\/p>\n

For theo\u00adret\u00adical consid\u00ader\u00ada\u00adtions of statis\u00adtics and testing, the average service life of the entire produc\u00adtion is used. To achieve shorter testing periods, often the thermal load is also set unre\u00adal\u00adis\u00adti\u00adcally high in order to achieve faster ageing of the compo\u00adnents. Changing oper\u00adating condi\u00adtions, which always occur in real-world appli\u00adca\u00adtions, are not taken into consid\u00ader\u00ada\u00adtion in this proce\u00addure. In order to make statis\u00adtical state\u00adments concerning fans, it is enough to take into consid\u00ader\u00ada\u00adtion the service life of the rotor bearing. Fail\u00adures of the elec\u00adtronics or the motor winding are signif\u00adi\u00adcantly smaller and can normally be neglected. On this basis, ebm-papst devel\u00adoped a diag\u00adnostic tool imple\u00admented in the fan that deter\u00admines the indi\u00advidual service life of the fan while taking into consid\u00ader\u00ada\u00adtion the respec\u00adtive ambient and oper\u00adating condi\u00adtions. This way the existing limi\u00adta\u00adtions of the oper\u00adating statis\u00adtics are completely rede\u00adfined by exact funda\u00admental data and the latest methods of calcu\u00adla\u00adtion.<\/p>\n

New approach<\/h2>\n
\"Bild2_Kompaktl\u00fcfter\"<\/a>

Figure 2: Compact fans with high output and internal self-diag\u00adnos\u00adtics for service life.<\/p><\/div><\/div>\n

The new service life predic\u00adtion takes into account the indi\u00advidual history of the fan in its respec\u00adtive oper\u00ada\u00adtion and thus state\u00adments about an expected remaining service life can be made in indi\u00advidual cases using the appli\u00adca\u00adtion condi\u00adtions. Changing temper\u00ada\u00adtures (day\/night cycles or seasonal fluc\u00adtu\u00ada\u00adtions) are taken into account, as are the accepted dust pollu\u00adtion on-site and the actual speed. This data is used by the elec\u00adtronics inte\u00adgrated in the fan to calcu\u00adlate the service life (Figure 2). The new early failure detec\u00adtion is conceived partic\u00adu\u00adlarly for users who can replace the fan only at high cost or at certain times (for example, remote measuring stations, radio buoys). With the new options, the replace\u00adment inter\u00advals can be planned in a timely manner or adapted to the indi\u00advidual require\u00adments. Fans no longer have to be \u201cpreven\u00adtively\u201d replaced, which reduces invest\u00adment and main\u00adte\u00adnance costs and increases oper\u00adating reli\u00ada\u00adbility.<\/p>\n

Real-world appli\u00adca\u00adtions<\/h2>\n

Instead of oper\u00adating on preset values, the new system uses data that is updated on an ongoing basis, such as oper\u00adating speed, ambient temper\u00ada\u00adture and down\u00adtimes. Basic data, such as the bearing design (ball or sleeve bearing), the type of bearing lubri\u00adca\u00adtion and the grease used, and other ambient condi\u00adtions is preset. That way service life reserves can be used, since the current fore\u00adcast always takes into account the overall history of the fan.<\/p>\n

\"Bild3_Restlebensdauer\"<\/a>

Figure 3a and 3b: The remaining service life can also be output digi\u00adtally via a PWM signal a) high, b) low or as an analogue value via an addi\u00adtional RC element.<\/p><\/div><\/div>\n

The diag\u00adnos\u00adtics system is based on empir\u00adical corre\u00adla\u00adtions from real-world appli\u00adca\u00adtions and decades of endurance tests under various condi\u00adtions. Customer-specific output formats, such as L5 instead of L10, can be taken into account. The output can be wired out via either the alarm wire or an addi\u00adtional wire and can be called up digi\u00adtally. The remaining service life can also be output as an analogue value via a PWM signal to an RC element. Thus the product can be used nearly up to the actual end of its life without losing reli\u00ada\u00adbility. That conserves resources, increases value creation and reduces costs of procuring replace\u00adments and main\u00adte\u00adnance costs (Figure 3a, b).<\/p>\n

\n

Service life or reli\u00ada\u00adbility<\/h4>\n

Service life and reli\u00ada\u00adbility are two terms that are often used and equally easy to mix up.<\/p>\n

Service life<\/strong>, often abbre\u00advi\u00adated to L10, spec\u00adi\u00adfies a period in hours during which up to 10 percent of the devices will have failed. An L10 value of 100,000 hours means that 90 % of tested devices have reached this run-time.<\/p>\n

In contrast, reli\u00ada\u00adbility <\/strong>is spec\u00adi\u00adfied with the value Mean Time Between Failure (MTBF). Since fans normally cannot be repaired, a more apt desig\u00adna\u00adtion would actu\u00adally be MTTF (Mean Time To Failure). Despite this, MTBF has become the expres\u00adsion that is most commonly used. State\u00adments regarding MTBF values only apply during the planned period of validity (e.g. usable service life). The failure rate can increase signif\u00adi\u00adcantly after that due to signs of wear. A MTBF value of 1,000,000 h (more than 110 years) means that if 1,000 devices were running at the same time, one of them would fail every thou\u00adsand hours, i.e. every 42 days (1,000 h * 1,000 = 1,000,000 h).<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

The life span calcu\u00adla\u00adtion gener\u00adally applied to fans today is based on the assump\u00adtion of statis\u00adtical aver\u00adages. For this, there are various calcu\u00adla\u00adtion formulas and eval\u00adu\u00ada\u00adtion criteria for loads such as temper\u00ada\u00adture, speed or dust and humidity. If oper\u00adating condi\u00adtions greatly deviate from the norm, this approach cannot provide any mean\u00adingful values for the actual [\u2026]<\/p>\n","protected":false},"author":12,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"wp_typography_post_enhancements_disabled":false,"footnotes":""},"categories":[5,16,10,9,15],"tags":[],"class_list":["post-7920","post","type-post","status-publish","format-standard","hentry","category-electronics","category-fans","category-machines","category-refrigeration-ventilation","category-telecommunication"],"acf":[],"_links":{"self":[{"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/posts\/7920","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/comments?post=7920"}],"version-history":[{"count":1,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/posts\/7920\/revisions"}],"predecessor-version":[{"id":18830,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/posts\/7920\/revisions\/18830"}],"wp:attachment":[{"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/media?parent=7920"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/categories?post=7920"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/tags?post=7920"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}