The MMTC 4-20-4 Coil Cord is a retractile spiral cable designed by MMTC Inc. for moving-door and gate applications. It provides a flexible wiring link between a traveling device and a stationary operator, helping maintain consistent signal transmission for components such as safety edges, photo eyes, and auxiliary controls on overhead doors, rolling steel doors, and commercial gate operators. This replacement part is commonly used in service, retrofit, and upgrade scenarios where a dependable coil cord is required to follow door travel and retract cleanly.
This model supports four-conductor low-voltage control circuits typically used with UL 325–compliant systems, including monitored or non-monitored sensing edges (verify wiring scheme with the operator manual). The coiled construction helps reduce cable strain and snagging during operation. For installation, secure strain relief at both terminations, route the cord to avoid pinch points, and leave adequate slack to prevent overextension. Use only for control wiring; do not run mains power through a coil cord. Always confirm conductor count and compatibility with the door or gate operator and connected safety devices before wiring.