16375 v9.0  Oct 12 
COMMUNICATIONS & NETWORKING............................................................................................................. 45 
Forming a Local Network of Hydran M2s .............................................................................................. 45 
Connecting the Hydran M2 to Hydran 201Ci Controllers ................................................................. 48 
Connecting the Hydran M2 to a D25 ....................................................................................................... 50 
MODIFICATION RECORD .................................................................................................................................... 51 
Table Of Figures 
Figure 1: Plastic Cap Must Remain in Place Until the Sensor Is Installed on the Valve ...................................................... 12 
Figure 2: Do Not Touch the Sensor’s Membrane with a Finger or an Object .......................................................................... 12 
Figure 3: Do Not Block the Sensor’s Breathing Hole or Puncture the Breathing Hole’s Membrane ........................... 13 
Figure 4: Do Not Install the Hydran M2 at an Angle, Vertically or Using an Elbow .............................................................. 13 
Figure 5: Do Not Install the Hydran M2 on an Elbow or a Fitting Box ......................................................................................... 13 
Figure 6: Do Not Install the Hydran M2 on the Inlet Side of the Radiator Pump ................................................................... 14 
Figure 7: Do Not Subject the Hydran M2 or Its Sensor to High-Pressure Water Streams ................................................ 14 
Figure 8: Do Not Paint the Sensor or Clean It with Any Solvent ...................................................................................................... 15 
Figure 9: Typical Installation of the Hydran M2 ....................................................................................................................................... 16 
Figure 10: Mounting Locations of the Hydran M2 on a Transformer .......................................................................................... 17 
Figure 11: Bottom Clearance ............................................................................................................................................................................ 18 
Figure 12: Tools Required for the Installation ........................................................................................................................................... 20 
Figure 13: Separating the Sensor from the Hydran M2 ...................................................................................................................... 21 
Figure 14: Disconnecting the Sensor Cable ............................................................................................................................................... 21 
Figure 15: Wrap the Sensor’s Threads with PTFE Tape ....................................................................................................................... 22 
Figure 16: Mount the Sensor Manually onto the Valve and Tighten it, Using an Adjustable Wrench ........................ 22 
Figure 17: The Bleed Screw Must Be on Top, at the 12 O’clock Position .................................................................................... 23 
Figure 18: Opening the Valve and Purging the Air from the Sensor ............................................................................................ 23 
Figure 19: Installing the Hydran M2 on the Sensor ............................................................................................................................... 24 
Figure 20: Grounding the Hydran M2 Enclosure..................................................................................................................................... 24 
Figure 21: Removing the Hydran M2 Cover .............................................................................................................................................. 25 
Figure 22: Installing Cable Conduits .............................................................................................................................................................. 26 
Figure 23: General Wiring of the Analog Input Terminal Block ....................................................................................................... 26 
Figure 24: Wiring of Self-Powered, Analog Inputs ................................................................................................................................. 27 
Figure 25: Wiring of Two-Wire, Loop-Powered, Analog Inputs ....................................................................................................... 27 
Figure 26: Wiring of Three-Wire, Loop-Powered, Analog Inputs .................................................................................................... 27 
Figure 27: General Wiring of the Analog Output Terminal Block ................................................................................................... 28 
Figure 28: Wiring of the 4-20 mA Analog Output Terminal Block.................................................................................................. 28 
Figure 29: Wiring of the 0-1 mA Analog Output Terminal Block .................................................................................................... 28 
Figure 30: Wiring of the Alarm Relays Terminal Block ......................................................................................................................... 29