Bard MC4002 Dual Unit Lead/Lag Controller Advanced Solid State

The Bard MC4002 is an advanced solid-state dual unit lead/lag controller designed to provide precise cooling control for two connected air conditioning units. This programmable electronic controller features two stages of cooling control available for each air conditioner, ensuring optimal performance and redundancy for critical HVAC applications.

Key Features:

• Controls two air conditioning units with intelligent lead/lag operation to balance runtime and extend equipment life
• Two stages of cooling control per unit for precise temperature management
• Compatible with systems with or without economizers and 2-stage or dual compressor configurations
• Four-character LCD digital display for building temperature readout and programming functions
• Electronic non-mercury design with programmable settings
• Isolation circuitry eliminates line or low voltage phasing requirements
• Operating range: 0 to 120°F, 18-32 VAC input, 50/60 Hz
• 10-second time delay between stages prevents short cycling
• Steel enclosure with hinged cover and 13 knockout holes (7/8" diameter)
• Front panel indicators show active cooling/heating stages and current lead unit
• Optional alarm board capability and Ethernet communication can be added later via simple snap-in installation
• Compatible with optional 8403-023A 35' remote sensor and 8403-038 humidistat
• Can be configured for heat pump applications with electric reheat dehumidification capability

The MC4002 base controller is ideal for telecom shelters, data centers, and other critical cooling applications where redundancy and precise temperature control are essential. The controller can be easily upgraded with optional alarm relay boards offering Form C dry contacts with both NO and NC switching for flexible alarm integration.