Staged cooling - Verasys - LIT-12013067 - LC-IOM3711-0 - LC-VAC1000-0 - LC-VAC3000-0 - Field Device - Verasys Constant Volume Controller

Verasys Constant Volume Controller Application Note

Product
Controls > Field Controls > Verasys Constant Volume Controller
Document type
Application Note
Document number
LIT-12013067
Revision date
2023-04-27

From the Details > System Configuration menu, you can configure staged cooling. The cooling coil is staged in sequence to maintain the zone temperature setpoint. You can set the Number of Stages Installed from the controller interface. If the cooling is set to 0 stages, cooling is not installed. A sequencer cycles through the following stages:

  • The first stage activates at 25% command and stops at 12.5% command.
  • The second stage activates at 50% command and stops at 37.5% command.
  • The third stage activates at 75% command and stops at 62.5% command.
  • The fourth stage activates at 100% command and stops at 87.5% command.

Navigate to Commissioning > Cooling to configure additional settings, for example, in Min on and off, interstage delay timers. When set to Enable, Rotate Enable controls the stages to balance the runtime equally. You can also set the discharge low limit parameter. If the discharge falls below a Supply Air Setpoint Cooling Min parameter, which is initially set to 50°F, cooling slows or stops. If OAT LOCKOUT Enabled is set to Enable, and the outside air temperature falls below the OA Cooling Lockout Setpoint the mechanical cooling becomes locked out.

For more information about commissioning cooling, see Table 1.