8.1.9 Gas Sens. Bad Alarm ......................................................................................................... 128
8.1.10 S. Card Comm Err Alarm .............................................................................................. 128
8.1.11 S. Temp C. Open Alarm................................................................................................. 128
8.1.12 S. Temp Hi Alarm ............................................................................................................ 129
8.1.13 S. Temp Low Alarm ........................................................................................................ 129
8.1.14 S. Tmp C. Short Alarm ................................................................................................... 129
8.2 RS-232 and RS-485 Communications ......................................................................................... 130
8.2.1 No Communication when the Host or Laptop Computer is Connected
Directly or by Modem to the Hydran M2-X’s DB-9 Connector ................................................ 130
8.2.2 No Communication when the Host or Laptop Computer is Connected
Directly or by Modem to the Hydran 201Ci Controller’s DB-9 Connector ........................... 130
8.2.3 No Communication between the Host Computer and the Network of
Hydran 201Ci Systems .......................................................................................................................... 131
8.3 Hydran M2-X and Hydran 201Ci Controller’s Analog Outputs at Zero ............................ 131
8.4 Alarms ..................................................................................................................................................... 132
8.4.1 Intermittent Gas Alarms................................................................................................... 132
8.4.2 An Alarm Relay does not Reset, even if the Alarm Condition has
Disappeared .............................................................................................................................................. 132
8.4.3 Irregular Gas Readings ..................................................................................................... 132
8.4.4 Inaccurate Gas Readings ................................................................................................ 133
8.4.5 Moisture Reading of the Hydran M2-X does not correspond with that
of a Validation Method .......................................................................................................................... 133
8.4.6 Moisture Readings Remain at 0% ................................................................................ 134
8.4.7 Irregular Readings (Moisture and Temperature) ..................................................... 134
9 Maintenance ............................................................................................................................................. 135
9.1 Cleaning the Enclosure Exterior .................................................................................................... 135
9.2 Replacing the Fuse ............................................................................................................................. 135
9.3 Replacing the Battery ....................................................................................................................... 136
9.3.1 Battery Specification ......................................................................................................... 136
9.3.2 Battery Life ........................................................................................................................... 137
9.4 Periodic Maintenance ....................................................................................................................... 137
9.4.1 History Files Verification .................................................................................................. 138
9.4.2 Dissolved Gas Analysis (DGA) ......................................................................................... 138
9.5 Maintenance Verification ................................................................................................................. 140
9.5.1 Visual Inspection ................................................................................................................ 140
9.5.2 Heater, Display and Keypad Verification ................................................................... 141