Mueller E-Star OESE 3.5 and 5 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828747
Effective April 13, 2020
8.4
RGE ELECTRONIC FAN PRESSURE CONTROL SETPOINT ADJUSTMENT
The RGE is factory set for use with R-507 and will energize the fan at minimum speed when the high-side pressure
rises above 190–200 psig. The fan motor should operate at full speed (1,075 rpm) when the high-side pressure rises
above 230–240 psig. This setting should be verified on initial startup.
To verify RGE operation, connect the high side of a manifold gauge to the liquid line service valve (P6). Energize
the condensing unit and monitor the fan operation in accordance with the high-side pressure. In low-ambient
conditions, the condenser may have to be partially blocked to increase head pressure.
To adjust the pressure range, remove the RGE cover and locate the adjustment screw (see Figure 6). To increase the
pressure range, turn the adjustment screw clockwise. To lower pressure range, turn the adjustment screw counter
clockwise. One turn of the adjustment screw will change the range by approximately 15 psig.
FIGURE 6: RGE ELECTRONIC FAN PRESSURE CONTROL
8.5
OFF-CYCLE FAN PRESSURE SWITCH
The off-cycle fan pressure switch is designed to protect the evaporator and the condensing unit from over pressure
during the wash cycle. The off-cycle switch will operate the fan at full speed if high side pressure rises above 270
psig and operate until pressure falls below 220 psig.
8.6
SCHRADER CORE IDENTIFICATION
All pressure switches will be marked with a red tie band indicating a Schrader core is present. If a pressure switch
connection does not have a red tie band, the refrigerant will have to be recovered before pressure switch removal.
NOTE:
All high-side pressure safety connections will not have a Schrader core due to safety regulation on the
system’s high side.
20
Cutoff Mode Switch
2
1
4
3
(CW)
Increase
the Set
Value
Decrease
the Set
Value
(CCW)
CSA
DFE0158
Adjustment Screw
Min
Speed
Cut
Off
160