Application Bulletin TM Altivar 66 AC Drive Purpose This Application Note explains when to select doormounted control devices without a manual speed potentiometer for Class 8839 Enclosed ALTIVAR 66 drives. Selecting Door-Mounted Control Devices Introduction Door-Mounted Control Devices Without Manual Speed Potentiometer Mod Number Description A09 Start/Stop Push Buttons C09 Start/Stop Push Buttons and Hand-Auto Switch E09 Stop Push Button and Forward/Reverse Push Buttons G09 Run/Stop Switch J09 Forward/Off/Reverse Switch L09 Hand/Off/Auto Switch When should you select door-mounted control devices without a manual speed potentiometer for Class 8839 Enclosed ALTIVAR 66 drives? Before choosing a general purpose device, ask yourself, “How will the speed of the drive be controlled without a local manual speed potentiometer?” Correct Reasons: • Manual speed potentiometer will be remote mounted from the drive. • Increase/decrease speed switches will be remote mounted from the drive. Incorrect Reasons: • Manual speed is controlled with a keypad, eliminating the need for the manual speed potentiometer. (See “Keypad versus Terminal” mode below.) • Manual speed potentiometer is assumed to be standard on the drive. • Perceived cost savings of a manual speed potentiometer is offset by expensive field rework costs. Keypad Versus Terminal Mode The Class 8839 Enclosed ALTIVAR 66 AC Drives are configured from the factory to operate in the Terminal mode. This mode activates the logic and analog inputs for interfacing with isolation/bypass contactors, process sequencing, and analog speed reference signals. NOTE: Switching from Terminal mode to Keypad mode disables all the I/O wired to the terminal strips, making external sequence logic inoperable. Application Bulletin Altivar 66 AC Drive Selecting Door-Mounted Control Devices (continued) The keypad is used primarily to program drive parameter functions and to display operational diagnostics. For example, a field sales representative specifies Mod “L09-Hand/ Off/Auto Selector Switch” for an enclosed AC Drive that has an isolation and bypass scheme. Hoping to save on unit cost, the keypad is used to adjust the speed instead of a door-mounted manual speed potentiometer. The Bill of Material consists of: Class 8839 Type 66UHG4VC (10HP @ 460 V) LO9-Hand/Off/Auto Selector Switch A11-24 V I/O Extension Module The right reason to specify this configuration: The end user plans to wire a remote 2.5kΩ speed potentiometer to control the drive in the Hand position. The wrong reason to specify this configuration: Using the keypad mode to control the drive will disable all external I/O required by the drive to operate. In this mode, neither isolation and bypass sequencing nor any remote interlocks will operate. 8800AB9601 July, 1996 Raleigh, NC, USA ALTIVAR is a trademark of Telemecanique S.A. or its successor-in-interest, Schneider Electric S.A. 2 © 1996 Square D All Rights Reserved Electrical equipment should be serviced only by qualified electrical maintenance personnel. No responsibility is assumed by Square D for any consequences arising out of the use of this material.