Stepper Unit Replacement

Model 722

Quickly replaces obsolete or unserviceable stepper units

Many older elevator systems use vertical selectors to determine car and landing position. These systems are complex and expensive to maintain—if parts can even be sourced.

Electrodyn’s Stepper Unit Replacement Model 722 is a solid upgrade that solves this problem by eliminating the need for vertical selectors. The board sends an electronic pulse to the machine room to indicate car/landing position. This economical retrofit is compatible with all control systems and is also available in a lift-off door cabinet.

Model 722 employs analogue relays that are far superior to chipset solutions in terms of price and maintenance. Step dampening prevents signal flutter, and rugged onboard 5-amp outputs ensure unit survival in higher voltage environments.

Key features:

• Position expansion capability is unlimited as four position units are mated.
• Installation is fast with average labor time of 3.5 hours for motor room wiring.

Interface

When installing the Stepper Unit, interface relays are matched to the control voltage and isolated from logic circuits. The interface is accomplished with a series of parallel connections, with one connection per position in each bank. Usually found at the main line input, an independent power source of 120/220 VAC is required. Both the bank inputs and power supply are fused.

During initial powerup, floor position is established at a terminal. During a power-loss event, car position is retained in the Stepper Unit's onboard memory. Model 722 recognizes the condition in which the car is behind the stepper when the stepper’s first position is reached, resulting in the car being sent to the top terminal for reset. Resetting is provided at both terminal landings.

Electrodyn's reliable Model 722 allows you to modernize your elevator system while maintaining high quality standards. Our technical support and application team is always available and our excellent service support is just a free phone call away.