Unit Options; Control Actuators; Enthalpy Control - Daikin RoofPak RPS Series Installation And Maintenance Manual

Control Actuators

The actuators are controlled by an analog signal from the
unit controller. Damper actuators utilize a 0-10VDC analog
signal while modulating heating/cooling valve actuators utilize
a 2-10VDC signal. Spring-return actuators are used for the
0 - 30% outdoor air and economizer dampers. The mixing
dampers are normally closed to the outside air.
Figure 94: Control Actuators Wiring Diagram

Enthalpy Control

Outside Air Enthalpy Control (OAE)
Units with MicroTech III control and an economizer come
standard with an electromechanical enthalpy control device
(OAE) that senses both the humidity and temperature of the
outside air entering the unit. This device has an enthalpy scale
marked A through D. Table 21
50% RH for settings A through D.
on a psychrometric chart. When the outside air conditions
exceed the setting of the device, the outside air dampers are
positioned to the minimum outside air intake position by the
MicroTech III controller.
Differential Enthalpy Control (OAE/RAE)
An optional electric differential enthalpy control arrangement
(OAE/RAE) is available on units with MicroTech III control.
In this configuration a solid-state humidity and temperature
sensing device is located in both the return (RAE) and outside
intake (OAE) airstreams. This OAE device has the same A
through D scale as the device described above. However, with
the OAE/RAE arrangement the switch on, OAE must be set all
the way past the D setting. With this done, the MicroTech III
controller adjusts the return and outside air dampers to use the
airstream with the lowest enthalpy.
IM 926-3 • ROOFPAK APPLIED SYSTEMS
shows the control points at
Figure 94 shows this scale
Table 21: Enthalpy Control Settings
Control Curve
A
B
C
D
Figure 95: Enthalpy Control Settings
5 0
( 1 0 )
,
4 5
( 7 )
4 0
( 4 . 5 )
3 5
( 1 . 5 )
3 5 4 0 4 5 5 0
( 1 . 5 ) ( 4 . 5 ) ( 7 ) ( 1 0 )
82

Unit Options

Control Point Temperature at 50% RH
73°F (23°C)
70°F (21°C)
67°F (19°C)
63°F (17°C)
8 5 9 0 9 5 1 0 0
( 2 9 . 5 ) ( 3 2 ) ( 3 5 ) ( 3 8 )
8 0
( 2 6 . 5 )
7 5
( 2 4 )
7 0
( 2 1 )
6 5
( 1 8 . 5 )
6 0
( 1 5 . 5 )
)
5 5
*
( 1 3 )
+
)
*
+
,
5 5 6 0 6 5 7 0 7 5 8 0 8 5 9 0 9 5 1 0 0
( 1 3 ) ( 1 5 . 5 ) ( 1 8 . 5 ) ( 2 1 ) ( 2 4 ) ( 2 6 . 5 ) ( 2 9 . 5 ) ( 3 2 ) ( 3 5 ) ( 3 8 ) ( 4 0 . 5 )
www.DaikinApplied.com
Unit Options
1 0 5
( 4 0 . 5 )
1 0 5