Bard MC4002 Solid-State Dual-Unit Lead/Lag Controller (No Alarm) — Replacement for MC4000

Overview: The MC4002 is an advanced solid-state lead/lag controller engineered to deliver accurate cooling control for paired air conditioner units. It is intended as a direct replacement for the MC4000 and functions as a standalone cooling controller in its basic configuration. Cooling stages: Each air conditioner receives 2 stages of cooling control, with the 2nd stage available for use with economizers or 2-stage compressors to optimize system efficiency. Humidity and reheat: The controller accepts a 2-wire humidity controller input to enable electric reheat dehumidification, improving moisture control when used in compatible cooling setups. Note: the electric reheat dehumidification feature is not supported when the MC4002 is configured for heat pump operation. Connectivity and upgrades: An Ethernet communication option is available for enhanced connectivity. If initially installed without alarms, the unit can be upgraded later by installing one of the optional alarm relay boards and plugging the communication cable into the main controller board. Alarm options and indications: Two variations of optional alarm relay boards are offered to provide different alarm capabilities. The MC4002 uses Form C dry contact alarm relays (supporting normally open (NO) and normally closed (NC) switching). All alarm events are displayed on the front panel, which also shows active cooling or heating stages and identifies the leading unit. Interface: A digital display provides temperature readout and is used for programming the controller.