Nidec Control Techniques HVAC Drive H300 HMI Bypass, Installation And Commissioning Manual

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HMI Bypass Controller Installation and Commissioning Guide 19
3.1.2 Main Control Screen
From the main screen, users can control the state of the bypass system and
navigate to system configuration (settings) and status menus.
HAND : Pressing this icon will put the bypass system in Hand Mode. In VFD and
Hand Mode, the system will run at a manually selected frequency and the
bypass contactor will automatically close if BYP (Bypass Mode) is selected and
the VFD output is off.
AUTO : Pressing this icon puts the bypass system in Auto Mode. In Auto Mode,
the system will require the “Auto Run Input” on terminal 27 to be active in
order to run the motor. If VFD Mode is also selected, the system will follow
the analog speed reference on terminal 5 (4-20 mA). If BYP is selected, the
system will run at line frequency, but still requires the “Auto Run Input”
(terminal 27).
STOP : This button will stop the motor and also acts as a reset.
Note: If a Remote Bypass, Remote VFD, or Fireman’s Override command is
present on the digital inputs, the STOP icon will not stop the motor.
VFD : Puts the system in VFD Mode. The output contactor is closed and the
motor is powered by the VFD.
BYP : Puts the system in Bypass Mode. The bypass contactor will close and the
motor will rotate at line frequency.
Note: If you are in Hand|Auto “VFD” Mode and want to switch To Bypass
“BYP” Mode, serlect Bypass Mode “BYP” and then reselect HAND or AUTO.