Limit Switches Technical Guide Introduction Rules and regulations What is meant by aposition detecto is any device which needs to be EC Directives operated by a member which exerts a physical force, in view of : Our detectors conform to the EC Low Voltage Technical Directive - either the form which its operating device takes 73/23/EEC and can be used in accordance with the specifications of the - or the considerable force needed to operate it Machinery Directive 89/392/EEC. The distinguishing features of position detectors are : - their high electrical performance capability Environmental conditions - their excellent resistance to accidental impact Temperature limits - good protection against splashed or dripping water When they are used in the temperature range quoted, the mechanical and - a wide range of operating devices to allow the detectors to be electrical characteristics of our position detectors will remain substantially adapted to a vast variety of mechanisms unchanged. If you intend to use them outside this range, please consult us. Protective treatment Construction The treatment given to our position detectors is suitable in the vast majority of applications. Our detectors are designed to conform to international IEC Parts made of steel are zinc-coated or painted according to their recommendations and/or European standards (EN). mechanical function. Further information is available on request. Proof that a detector conforms to these standards or recommendations This treatment allows our detectors to be used under the following takes the form of a conformity declaration made by the manufacturer temperature and humidity conditions : (drafted as indicated in guidance document ISO/IEC 22 - EN 450-14). Characteristics in line with the general requirements of standards NFC T C 20 40 50 Relative humidity % 95 80 50 63140, IEC 947.5.1 and EN 60947.5.1. This treatment may thus be suitable for applications in tropical or equatorial - Leakage paths and air gaps : IEC 664.1 - NFC 20-040. climates where the equipment concerned is in an interior location sheltered Our position detectors which comply with IEC 947.5.1 can be fitted to from direct exposure to atmospheric conditions. machine-tools and industrial machines complying with NFC 79130, IEC Other types of reinforced protection are possible for resistance to very severe 204.1, EN60204 or VDE 113. environments. Please enquire. Mounting requirements Electrical characteristics Electric shock protection. Assigned working current (Ie): The user should observe the mounting instructions relating to the mode of - the current level adopted as a basis for the operating conditions quoted protection against electric shocks defined in the IEC 536.1, EN 60204.1 - for a detector, and for the life tests on it. NFC 20030 standards : Class I : earth circuit link. Protection via differential circuit-breaker. Thermal rating (Ith): Class II : double insulation. - the current the microswitch will withstand when not being operated Class III : very low safety voltage. electrically, for a temperature rise of not more than 60 C. 2 Screw tightening torque : Assigned insulation voltage (Ui): 1 : Actuator tightening 1.2 to 1.5 Nm 1 - the voltage adopted as a reference for the dielectric tests and leakage paths. It must be equal to or greater than the assigned working voltage. 4 Plastic Metal 3 body body Categories of use (IEC 947.5.1): 3 2 : Head fixing screw 0.7 to 0.8 Nm 0.8 to 1 Nm - AC 15 for operating AC solenoids and electromagnets 3 : Body fixing screw 0.7 to 0.8 Nm 0.8 to 1 Nm - DC 13 for operating DC solenoids and electromagnets 4 : Fixing screw 2 to 2.5 Nm Contact element designation Adjustment of rotary heads with momentary action to right and left : (IEC 947.5.1): For series 83 850, 83 851, 83 861, 83 854, 83 855, 83 863 - a letter and number which define the use category and the assigned working voltage and current For example, A 300 means : in category AC 15, a maximum working 10 (x 360) voltage of 300 V and 6 A at 120 V or 3 A at 240 V. Contact block electrical wiring diagram Form Za Form Zb Degree of protection Both contacts have the The 2 contacts are Under the IEC 529 or NFC 20010 classification scheme, standards employ same polarity electrically isolated an IP code to define the degree or class of protection which a position detector provides against access to live components and against the entry Positive break contact operation (IEC 947-5-1, chapter 3) of solid foreign bodies and the entry of water. For contacts used in safety applications, limit switches, emergency stop devices, assurance that opening has occurred is essential (see IEC 204, EN60204). After each attempt, contact opening is checked by an impulse st 1 numeral voltage test (2500 V). Protection equipment provides Protection for persons against Contact element : against the entry of solid access to dangerous parts - Snap action contact foreign bodies This is characterized by tripping points and release points which cannot 0 (not protected) (not protected) be confused. The speed at which the control devices moves is 4 diameter 1 mm 1 mm wire independent from the speed of the control device. This feature makes it 5 protected against dust 1 mm wire possible to obtain satisfactory electrical performance even where the 6 sealed against dust 1 mm wire control device is moving at low speed. A : Total travel (TT) of the control device nd 2 numeral A B : Pre-travel (PT) until the contact element Protection equipment provides against the entry of water B opens F C : Release travel until the contact element 0 (not protected) 6 high-pressure hosed water closes 4 splashed water 7 temporary immersion 0 5 hosed water 8 prolonged immersion D : B-C = Differential travel C D F : Travel required to reach the positive opening point (POT) Products and specifications subject to change without notice. Order/Technical Support Tel: (800) 677-5311 / FAX: (800) 677-3865 / www.crouzet-usa.com 3/111TT POT DT OT PT Mechanical characteristics Terminology Forces - Positions - Travel OF POF TTF RRF RP TP OP POP OL RLP NC NO OF Operating force POF Positive opening TTF Total travel force RRF Release force force Force which must be Level to which the Force applied to the applied to the operating Operating force applied operating device to move operating force OF must device to displace the to the operating device it through its total travel. be reduced to allow the rest position RP to the mechanism to return to to cause the positive tripping point TP. opening action to take its release position RLP. place. TP Tripping point OP Operating point POP Positive opening OL Overtravel limit RP Rest position RLP Release position point Position of the operating Position of the operating Position of the operating Position of the operating Position of the operating device when no external device in relation to its device when the applied Position of the operating device when the force device at the moment mechanical force is mounting (hole, face) at force has moved it to the device at the moment applied has brought it to the when the snap-action applied. Also described the moment when an point on its travel where when a force produces the effective end of its permitted mechanism trips on its asheight at res. operating force causes mechanical and electrical positive opening action. travel without causing return to its original the snap action of the operation of the detector damage. position. mechanism to trip. can be relied on to occur. POT Positive opening TT Total travel PT Pre-travel OT Operating travel DT Differential travel travel Distance between the rest Distance between the rest Distance between the Distance between the position RP and the rest position RP and the Minimum movement of position RP and the tripping point TP and the operating point OP. tripping point TP. the operating device overtravel limit OL. release position RLP. required to ensure that the opening contact is positively opened. - Positive opening action : see IEC 947-5-1 chapter 3, 2.2 N.B. : The max. and min. values quoted for each detector (min. operating force, max. total travel, etc.) are the maxima and minima users must allow for if they are to use our products under the proper conditions. Products and specifications subject to change without notice. Order/Technical Support Tel: (800) 677-5311 / FAX: (800) 677-3865 / www.crouzet-usa.com 3/112 Electrical Position of operating device Travel Positions Forces circuit PT OT POT TT DT