The Robertshaw SlimZone® Premier zone panel is ideal for light commercial applications. It’s a constant volume zone system that controls 3 to 19 zones from a single heating and cooling unit. Dedicated thermostats in combination with motorized dampers serve each zone. The control module monitors the zone thermostats and energizes the HVAC system to the requested mode of operation. The SlimZone® Premier automatically controls equipment staging, and all setup and monitoring is achieved by a 4-button keypad with a 4-line by 20-character LCD display. The basic system consists of the SlimZone® Premier control module which controls up to 3 zones. Additional SlimZone® expansion modules add 2 zones per module and up to 8 expansion modules can be connected to the system for a total of 19 zones. The SlimZone® Premier requires a DSL-520P communicating zone thermostat for each zone. The zone panel is wired to HVAC equipment. A dedicated 24 VAC, 75 VA transformer is needed to power the zone panel. Separate transformers are required for the zone dampers. The SlimZone® Premier provides power to the DSL-520P communicating zone thermostat and any expander modules.