The OHMIC RESISTORS Pty. Ltd.

Transcription

1 The OHMIC RESISTORS Pty. Ltd.

2 The operating mechanism is arranged between and above two steel end plates held apart by three mild steel spacing rods. The handle mechanism is mounted above the top plate. The cam contactor assembly and indexing mechanism runs between the two plates, the bottom plate housing the lower bearing. The substantial square section steel operating shaft is supported by ball bearing assemblies which are bolted to the end plates and it carries moulded thermosetting phenolic discs to which detachable cams are screwed..1ax 6 Circuit\ The detachable cams are available in a range of profiles which provide any required sequence of operation. The cams are keyed onto the discs and are secured by set screws. The stepping arrangement comprises a spring loaded ball mounted beneath the top plate operating over notched serrations in a case hardened steel plate, providing positive location of each step with minimum effort. The OFF position stop arrangement comprises a spring controlled latch in the handle which rises into the notch in a steel plate bolted to the drive mechanism housing and is released by light downward pressure. Stop studs which limit the travel of the operating handle in either direction are separately adjustable. NUMBER OF CIRCUITS CONTR OLLER TY PE A B C D Construction Fixed and moving contacts are of the fine silver double break type, commonly used in other Hawker Siddeley Switchgear mill type equipment. Terminals are fitted with cup washers and large capacity clamping nuts. Operation of the contacts is by spring closure and mechanical opening. Both fixed and moving contacts are enclosed in a moulded phenolic housing, which has a flash barrier between each pair of contacts, and considerable creepage distance between live metal and live metal, and live metal and earth. Contact opening is accurately set for efficient operation throughout the life of the contacts and needs no adjustment. Selection of Controller Types Four basic types of standard controllers are available, depending on the number of circuits required and the space available for mounting. The table shows the number of circuits available for each type while the diagram indicates the sizes and general appearance. Attachment Details Spring Return This feature can be fitted as an extra to A, B and Joystick controllers to provide automatic return to the 'off position when pressure is released from the handle. On Joystick models, the spring return mechanism can be fitted to provide return on either motion or both motions. Provision is made for fitting spring return to controllers without increasing leading dimensions and a kit containing all the necessary parts is available for fitting in the field. Base Strap Mounting Where the controller cannot be readily mounted in the normal fashion using the holes in the baseplate, base straps can be provided which allow for fixing outside the normal controller base. Twin Drive This optional feature provides means of operating two controllers simultaneously while also enabling them to be used independently if desired. A simple 'H' bar is used to interlock the two operating handles and is easily removed to enable independent use.

3 Typical application is for use on cranes with twin hoists or holding and closing lines, as on Grab Unloaders where dual motor, single hoist operation is required; i.e. wharf cranes. Dimensions Basic Model Deadman 's Handle This incorporates a push button operated micro switch, mounted within the handle assembly to provide electrical interlocking capable of isolating the controller circuits if the pushbutton is not depressed when the handle is away from the "off' position. The preferred interlocking for use with this device is one which opens a contact in the holding circuit of the main contactor if the button is not held down. Deadman's handle is not available on joystick models or crank handles and, although it is recommended that this feature be used with spring return, it is not essential. *DIMENSION T IS THE DISTANCE F ROM CENTRE LINE OF HANDLE TO LEADING EDGE OF CONT ROLLE R. Crank Handle The tramway type control handle is provided at no extra cost where this type of control is preferred or where designs are such that the controller is used in a horizontal position and the vertical handle is no longer practical. Option Notes Operating Handles Type A and C Controllers are fitted with a 'long' handle while types B and D are fitted with a 'short' handle. Where spring return is used on type B controllers, they will be fitted with 'long' handles unless otherwise specified. This increases dimension R for type B by 57mm. Auxiliary Switch An auxiliary switch can be fitted to all controllers to provide an OFF position interlock and is attached to the controller in the position normally used for the spring return mechanism. The use of this auxiliary is only necessary where the maximum number of circuits are fitted and connected for. Qther purposes.

4 The Ohmic Resistors Pty. Ltd.

5 *Automatic ' release catch on moving section. *Access to terminal board from all sides. *Lifting handles - no ropes or pulleys required. *Ideal for installation in confined spaces. Controller Types 1. Free standing model (716 WFS) with: *Lift-off covers all round at base for access to mounting holes and terminals. *Easily removable terminal board - no screws or nuts - maximum 20 terminals. *Cable entry from underneath or two sides. 2. Clutch operated model (716 WCT) with: *Robust mechanical interlock preventing access to controller unless it is in the "Off ' position. *Optional l.8m length of control cable to allow connection to a suitable external terminal board - specify at time of ordering. Attachments Spring return - can be provided on all models, but is not recommended for clutch operated controllers. Deadman's Handle - Available on all models except Joystick. Crank Handle - Available in all models except Joystick. Application The controller will suit any application requiring the control of contactor coils. It has been designed to provide a versatile contact arrangement and to suit installation in areas of limited space or in control consoles. The controller is suitable for use on both AC and DC inductive circuits. For AC Volts 10 Amps For DC -480 Volts 0.5m Amps or 230 Volts 1.75 Amps How to Order Specify controller type (716 WFS or 716 WCT), attachments required, and provide details of circuit for setting of cams or an arrangement diagram. Loose cams can be provided if required, specify cam numbers and quantities. Dimensions Installation Fix controller to any rigid surface by using the mounting holes provided in the base plate. The controller should be installed in the upright position. Units are supplied unwired unless specified at time of ordering. Maintenance No lubrication is required - in fact it can be harmful. An occasional inspection should be made to check tightness of terminal screws and possible contact wear. Do not use emery cloth on contacts. DIMENIONS IN MM

6 Spares No. Description Part Number Sprlng retu rn feature supplied as an ex tra If requ ired 24 Return spring No. Req'd 1 Handle rod & knob assembly Complete drive assembly S9 Ball bearing Latch plate Latch Handle spring Handle stop stud Sl2 Ball bearing Indexing Cam drum Indexing Segment Indexing Ball Ball spring Fork pin Shaft bush Shaft fork Contact panel assembly As Req'd 17 Fixed contact As Req'd 18 Moving contact As Req'd 19 Contact spring As Req'd 20 Contact panel spring As Req'd 21 Cam drum As Req'd 22 Side cover Access cover Specify short or long handle CAM NO 2 Installation Fix controller to any rigid surface by using the mounting holes provided in the base plate (or in top plate for desk mounting). The controller can be installed in any position. Operation is not affected by the angle of mounting. Maintenance No lubrication is required - in fact it can be harmful. An occasional inspection should be made to check tightness of terminal screws and possible contact wear. Do not use emery cloth on contacts. How to Order Specify controller type, floor or desk mounting, attachments required and provide details of circuit for setting of cams or arrangement diagram. Loose cams can be provided if required; specify cam numbers and quantity.