Asco — Installation and Reassembly

A Asco service procedure — check it applies to your exact model before use.

Procedure

1. Reconnect the terminal lugs. New contact plate should be clean before reattaching terminal lug. Carefully secure each new stationary contact plate in a vise. From the back insert the terminal screw with new bevel washer throught the stationary contact plate into the terminal lug (stepped edge on side). Tighten the teminal screws to 175 in–lbs. ! To prevent overheating, screws to 175 in–lbs. torque the terminal
3. Install new arc runners. Carefully secure each new stationary contact plate in a vise. Install new arc runners flat against the plate by using a phillips screwdriver to install (cw) the two screws. Be sure that the formed side is out, that the jaws are on both sides of the contact button, and that it is positioned as close as possible to the contact button.
2. Install new stationary contact assemblies. Insert each new stationary contact (with terminal lug & arc runner) into the molded base and secure it by installing two hex nuts with flat and lock washers behind the base. Use a 7/16” socket wrench to tighten nuts. Movable Contacts Reassemble as shown in Figure 4, page 3.
1. Apply conductive lubricant to shunt lugs. Use a cotton swab or small brush to apply conductive lubricant 263300 to the exposed surface of each shunt lug in the shaft. ! ! To prevent overheating, torque movable contact screw to 100 in–lbs. To prevent bind check contact for free movement in shaft.
3. Install new contact springs. Press a new spring onto the head of each screw that secures a movable contact.
4. Install contact spring retainer. into the cavities of Place the spring retainer onto the springs so that they seat the retainer. Compress the springs with the retainer and hold it in position. Use a 5/16” nutdriver to install (cw) the four # 10–32 hex head (Sems) screws with shake washers to secure the spring retainer to the shaft. Tighten the screws.
5. Check contact deflection. Lift tip of each movable contact to verify freedom of movement in the shaft. If there is binding, loosen the contact screw enough to reposition the shunt lug slightly, then retighten the screw to proper torque. Recheck deflection.
6. Install all arc chutes. Tip the arc chute while placing it over the stationary contact. Slide the arc chute toward the shaft (up or down) until it stops. Then position it so that it is centered over the stationary contact, and so the movable contact does not strike the arc chute plates. Secure arc chute to the panel by using a screwdriver to install (cw) nylon retainer nuts on both sides of arch chute. Torque the nuts to 12–14 in–lbs.
7. Slowly manually operate switch with the manual handle. Check contact clearance with arc chutes.
8. Install barrier/pole cover. Place the cover against the arc chutes. Use a phillips screwdriver to install (cw) four screws in cover. Failure to use conductive lubricant 263300 between shunt lug and contact may cause overheating. !
2. Install new movable contacts. Place a new contact on the shaft and secure (cw) it to the shunt lug with the new 1/4–20 screw and lockwasher. Each screw with lockwasher passes through the contact stiffener and movable contact, into the shunt lug. Tighten the screw by using a 5/32” hex bit or allen head driver to 100 in–lb. To prevent the possibility of personal injury or property damage, be sure to install the insulator backing piece behind the transfer switch when reinstalling it. ASCO POWER TECHNOLOGIES L.P. 50 Hanover Road, Florham Park, New Jersey 07932 USA www.asco.com 381339–126 5 Operator Coil Replacement (coil kits listed below) 2 pole switch switch service voltage switch with Acc. 28* 260 amp switch Coil Kit No. 3 pole switch 400 amp switch Coil No. 3 pole switch 343501–1 343501–21 343501–31 110–120 V 343501–1 343501–21 343501–31 343501–2 343501–22 343501–32 208 V 343501–2 343501–22 343501–32 220–240 V 343501–3 343501–23 343501–33 343501–3 343501–23 343501–33 440–480 V 343501–5 343501–25 343501–35* 343501–5 343501–25 343501–35* 343501–6 343501–26 343501–36 550–600 V 343501–6 343501–26 343501–36 switch with Acc. 28* 2 pole switch Rectifier Kit Number 411785 411785 411785 411785 411785 *Use coil kit 343501–34 only for 440–480 V, 3 pole, switched neutral transfer switches with continuous edge base (starting mid 2003). See illustrations below. notched base left side of control contacts before mid 2003 continuous edge base (without notch) starting mid 2003 Removing Coil Assembly ! To prevent the possibility of personal injury or property damage, disconnect all power sources to the switch before working on it. The coil assembly is mounted to the top left corner of the base with two screws. It must be removed to a work bench for disassembly.
1. Close the top main contacts. Use the manual operator handle to put the switch in the Emergency position. See page 2.
2. Disconnect the rectifier. Pull off the four terminal lugs from the square rec- tifier mounted on the coil frame, then bend the wire leads away from the coil assembly.
3. Remove the clip assembly. Use a 5/32” hex key wrench to remove (cw) two screws with lockwashers from the frame, then re- move the coil assembly. ! To prevent the possibility of personal injury or property damage, hold coil assembly securely when removing screws. Spring exerts substantial force on coil assembly.
4. Remove the core spring. Leave the core and link hooked onto the weight pin, but remove the core spring from the core. Disassembly The solenoid coil is held in the frame by the core tube. The retaining ring secures the core tube and stub core. See Figure 6.
1. Remove the retaining ring. Use a screwdriver to pry the retaining ring out of the groove in the stub core which extends through the frame.
2. Remove the core tube and stub core. Pull the core tube out through other end of frame. The stub core will come out with the core tube.
3. Remove the coil and washers. Pull the coil and washers out the side of the frame. 381339–126 6 ASCO POWER TECHNOLOGIES L.P. 50 Hanover Road, Florham Park, New Jersey 07932 USA www.asco.com Operator Coil Replacement (continued) retainer ring frame rectifier spacer washer spring washer coil core tube stub core Indicates parts included Coil Kit
3. Install the retaining ring. Use pliers to slide the retaining ring into the groove in the stub core to secure the core tube

Source: manual:381339-126_C_1 e frame.pdf. Figures and steps are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.