Type 4111 and 4121 mill duty dynamic lowering hoist
controllers for crane service are built with four, five or six speed points
using mill duty components throughout. Dynamic lowering control
panels are suitable for use with DC series motors on crane hoist drives
without a mechanical load brake and for use with a power limit switch.
Standard circuit features include:
Complete operator control, hoisting and lowering.
High speed no-load hoisting and lowering
Off point dynamic braking.
Positive series brake operation with all loads.
Smooth definite-time acceleration.
The Type 4111 is a NEMA class 1 controller with 5 or 6
speed points, negative line M contactor, and electronic overload relay
The Type 4121 is a NEMA class 2 controller with 4 or 5
speed points and thermal overload protection.