OVERVIEW
4
RSMD Technical Guide
Features & Applications
The OE370-26-RSMD Refrigerant System Module for Digital
Compressors (RSMD) (AAON Part No: V61520) can monitor and
control up to two compressors and condensers. The compressors can
be in either a tandem or non-tandem confi guration. The module is
designed for R410-A refrigerant.
The RSMD is connected to the VCC-X / VCCX2 Controller.
Up to 4 RSMD’s can be connected, depending on the size of the
system. There are 2 E-BUS Expansion Ports which allow the use of
communicating sensors and the E-BUS Modules.
The RSMD provides 3 analog inputs, 4 binary inputs, 5 relays, and
2 analog outputs. See Figures 2 & 3, pages 6 & 7 for wiring.
The RSMD Module provides the following:
• Modulates the Compressors to satisfy the Suction
Coil (Saturated) Temperature. The Suction Coil (Satu-
rated) Temperature Setpoint is reset by the VCC-X /
VCCX2 Controller to maintain the Supply Air
Temperature during Cooling mode. During Dehumidi-
fi cation mode, it controls the Compressors to the
Suction (Saturation) Temperature Setpoint.
• In Heating mode, the RSMD modulates and stages
the compressors to maintain a given Supply Air
Temperature Setpoint.
• Modulates the Condenser Fan or Valve to maintain
the Head Pressure Setpoint.
• Provides alarms and safeties for the Compressor and
Condenser operation.
• Allows connection of the Modular Service Tool SD
to the module when required communication wire is
run to the VCC-X / VCCX2 Controller.
• Provides a 2 x 8 LCD character display and 4 buttons
that allow for status of system operation, system
setpoints, system con gurations, sensors, and alarms,
and to change the module’s address, if necessary.
RSMD Overview