Adjustable-speed Pacemaster DC Drives are robust, rugged and reliable. Pacemaster 4 provides four-quadrant operation and is available in 1/4 to 2 HP ratings, operating from single phase 115 or 230 VAC. Pacemaster 5 provides four-quadrant operation and is available in 3 to 5 HP ratings, operating from single phase 230 VAC. Each drive solution provides linear performance and EMI noise immunity.

GENERAL DESCRIPTION

Pacemaster 4 & 5 adjustable speed DC drives are bi-directional regenerative (four quadrant operation) units developed for control of permanent magnet or wound field DC motors used in applications with high duty cycles, overhauling loads requiring hold back torque, or the need for controlled stopping. The basic characteristics are controllable bi-directional torque, reversing, regenerative braking and rapid response to speed change signals.

Pacemaster, Regenerative DC Drives for Four Quadrant Operation

115/230V • 50/60 Hz • SINGLE PHASE

1/4-2 HP & 3-5 HP

STANDARD FEATURES

• Four quadrant speed/torque control.

• Operates on 50 or 60 Hz, for worldwide applications.

• Encapsulated SCR packs contain all power semiconductors for increased reliability and minimal maintenance time.

• Burst firing to SCR gates helps prevent unstable operation. • Electrically isolated heat-sink.

• Isolated armature voltage impedance feedback or tachometer feedback, selectable by internal DIP switch.

• AC line isolated current feedback.

• Two-mode stopping (coast and regenerative braking).

• Control circuit relay helps to protect against automatic restart of equipment after return of interrupted AC incoming power.

• Temperature compensated reference.

• Plus and minus 6.2 volt supply allows contactorless reversing with center tapped pot.

• AC line fuses on standard chassis models or circuit breaker on NEMA 12K enclosed models for short circuit protection. Protection must be supplied by the customer for the Mini-Chassis model.

• Armature DC fuse.

• Fused isolation transformer for magnetic and The Pacemaster 4 is available in ratings from 1/4 to 2 HP, and is re-connectable to operate from single phase 115 or 230 VAC input power. The Pacemaster 5 is available in 3 and 5 HP ratings, and operates from single phase 230 VAC input power. Both are offered in a choice of open chassis or NEMA 12K enclosed models. All units utilize dual back-to-back bridges, consisting of four SCR's each, to provide full wave power conversion for smooth efficient operation and high performance. Conservatively rated power components and pre-conditioned and tested logic semiconductors assist in providing reliability and long service life. Pacemaster 4 & 5 drives are designed and manufactured to comply with applicable standards established by the National Electrical Code and NEMA for industrial motor and control equipment.

• Fused isolation transformer for magnetic and reference circuits.

• MOV transient voltage suppression to minimize the effect of voltage spikes from the AC power source.

• dv/dt and di/dt power semiconductor protection.

• Bank selection current lockout protection.

• Adjustable minimum and maximum speed, current limit, IR compensation and stability.

• Armature voltage limit to provide reliable SCR commutation in the regenerative mode.

• Mini-Chassis model is UL recognized.

AVAILABLE OPTIONS

• Armature Contactor

• Dynamic Braking

• Tachometer (Voltage) Follower

• Isolated Tachometer (Voltage) Follower

• Isolated Process Follower

• Linear Accel and Decel

• Dancer Follower

• Field Supply Kit

• Operator Controls for Local or Remote Mounting