01. MADG-0107 7/5/07 9:17 AM Page 120 Actuator Controls Actuator Controls Rotary Limit Switches Screw Traveling Nuts Input Shaft SKA Series Rotary Limit Switch Gear Nut Guide Precision Features • Available in two control voltage ratings: 250 or 480, and in three gear ratios. • Can be used in applications where there is a need to control equipment that rotates and/or reverses. • Sturdy and compact. Constructed of corrosion-resistant materials, with housing of black anodized aluminum. Meets NEMA-4 water tightness requirements. • Simple to adjust. Two switches, one for up/stop and one for down/stop, are activated by the adjustable limit-switch nuts which travel laterally when the internal screw is rotated through gear reduction. • Operating temperature range -20° to + 150°F. • Lifetime lubricated. • Can be mounted on right or left extension of actuator worm shaft in any of four quadrants. • Optional 4-position limit switch available. Consult factory for dimensions. To ensure that limit switch has sufficient travel capability for the actuator unit, use the following formula: Maximum raise of actuator model in inches = Maximum Input Revolutions Turns of Actuator Worm per Inch of Raise Note: For water-tight connection, use a weather-tight connector and sealant around threads. Limit switches will be damaged if overtraveled. For shipping purposes, the 1/2" NPT hole is closed with a plastic plug which is not water tight. For additional assistance, contact our Customer Service at (800) 477-5002 120 01. MADG-0107 7/5/07 9:17 AM Page 121 Actuator Controls Actuator Controls Rotary Limit Switches Rotary Limit Switch Performance Specifications Max. Voltage Max. Amps Gear Max. Max. Max. Allow- Notch Model No. AC DC AC DC Ratios Worm Rev. Rise able Drift Adjustment SKA6000AT10 10:1 1095 1095/TPI 24/TPI 1/TPI 250 SKA6000AT20 15 20:1 2190 2190/TPI 48/TPI 2/TPI SKA6000AT40 40:1 4380 4380/TPI 96/TPI 4/TPI SKA6000BT10 125 .50 10:1 750 750/TPI 29/TPI 1/TPI SKA6000BT20 480 15 20:1 1500 1500/TPI 57/TPI 2/TPI SKA6000BT40 250 .25 40:1 3000 3000/TPI 115/TPI 4/TPI TPI = Turns per Inch of Raise of Actuator Unit Rotary Limit Switch Mounting and Adjustment All models except 75, 100, Switch position and 150 ton 75, 100, and 150 ton only www.duffnorton.com • Ph: (800) 477-5002 • Fax: (704) 588-1994 121 01. MADG-0107 7/5/07 9:17 AM Page 122 Actuator Controls Actuator Controls Rotary Limit Switches Limit Switch Field Installation Dimensions Worm Shaft Dimensions "B" Mounting Worm Capacity Dimensions Shaft Dia. 2 & 3 Ton MS 6 3/4 .500 3 Ton BS 6 3/4 .625 5 Ton MS & BS 7 3/4 .750 10-15 Ton MS & BS 8 3/4 1.000 20 Ton MS & BS 8 3/4 1.000 25 Ton MS & BS, 35 Ton MS 10 1/4 1.375 Note: Limit switch cannot be fitted 50 Ton MS & BS 14 1/4 1.500 directly to 1/4,1/2 and 1 ton series. 75 Ton MS 15 1/4 1.750 Antibacklash mounting is the same as 100 Ton MS 14 3/4 1.750 Machine Screw Actuators. Dimensions are subject to change without notice. 150 Ton MS 14 3/4 1.875 Rotary Limit Switch Electrical Wiring Diagram and Setting Instructions 1. CAUTION: Disconnect power before making any adjustment. 2. Check drift before adjusting limits. 3. Remove screw "A" and nut guide keeper "B" to adjust limits. 4. Run actuator unit to desired limit. 5. Rotate appropriate nut until switch clicks, then turn 1/2 turn more. 6. Replace "A" and "B. " 7. Run actuator unit to other limit. 8. Repeat steps 2, 4 and 5 to adjust this nut. N.O. = Normally Open N.C. = Normally Closed Slight adjustments may be necessary. See Performance Specification Chart on the previous page for notch adjustment value. For additional assistance, contact our Customer Service at (800) 477-5002 122