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BA490

BA490
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Zone 1,2, 21,22 or safe area BA490 Rotary encoder Robust control knob with quadrature output General purpose Instrument with quadrature input such as BA427E Closed - Open Closed Clockwise rotation —- The BA490 encoder is a robust panel mounting rotary control knob with a quadrature switch contact output, suitable for installation in hazardous or safe process areas. It is designed for easy adjustment by a gloved hand and may be directly connected to almost any instrument that accepts a three-wire quadrature input to provide a simple way of making adjustments from within the process area. The encoder contains two single pole switches that open and close 90 degrees out of phase with each other as the control knob is rotated. This enables both the position and direction of rotation to be determined. If switch ‘A’ leads switch ‘B’, the knob is rotating in a clockwise direction, if ‘B’ leads ‘A’, the knob is rotating in a counterclockwise direction. A common application for the BA490 encoder is to provide rotary manual control of a BEKA BA427E or BA627E 4/20mA output Set Point Station. Normally the output current of these generators is controlled by the front panel ▼ and ▲ push buttons, but direct connection of the BA490 rotary encoder enables an operator to make adjustments via the conventional rotary control knob. Compliance with Simple Apparatus requirements specified in Clause 5.7 of the international intrinsic safety standard IEC 60079-11 allows the BA490 encoder to be installed in Zones 1, 2, 21 and 22 and to be directly connected to intrinsically safe apparatus located in the same hazardous area. IP65 sealing of the control knob and the joint between the encoder and the panel prevents ingress when installed in a panel that will be hosed, washed or splashed. When environmental protection behind the panel is also required the BA599 rear sealing assembly accessory provides IP65 protection allowing the encoder to be fitted in a panel with an open back. u Quadrature switch contact output. u Robust construction U Simple Apparatus allows installation in a hazardous area. u IP65 front of panel protection. U 22.5mm hole mounting. u 3 year guarantee www.beka.co.uk/ba490

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DIMENSIONS (mm) Contacts Rating Current Output Phase Switch ‘A’ leads switch ‘B’ by 90° for clockwise rotation of the control knob. Single fixing hole 22.5 ±0.2 M-»+«- 12 pulses per 360° rotation of the control knob. Nil Insulation Voltage to conductive panel. Gland for 7 to 12 outside dia cable < Intrinsic safety Code Complies with the requirements for Simple Apparatus specified in Clause 5.7 of IEC 60079-11. Optional BA599 rear sealng assembly Environmental Operating temp Storage temp Humidity Enclosure Front IP65, rear IP20, see accessories for optional BA599 IP65 rear sealing...

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