Electro-Chemical Devices (ECD) HYDRA Ammonium - Manual (Page 13)

HYDRA NH
4
+ -N Page 5
2.0 INSTALLATION
2.1 UNPACKING
Carefully remove the HYDRA sensor from its shipping container. Inspect the sensor for damage. Verify
the electrodes, Ammonium, Potassium and pH and the Spray Cleaner Nozzle are installed in the sensor
housing. The electrodes should be hand tightened into place so that the sealing o-rings are not visible.
The electrodes are supplied with protective caps that must be removed before start up. Do not remove
the caps until ready to use.
### NEVER SUPPORT THE HYDRA SENSOR BY THE CABLE, IRREPAIRABLE DAMAGE WILL OCCUR ###
2.2 ASSEMBLY
The HYDRA Sensor is shipped completely assembled, before use it must be connected to the analyzer
and an air supply. Connect the spray cleaner feed tube to a compressed air supply controlled by a
solenoid valve (not supplied). Attach an immersion/support tube (not supplied). Finally connect the
sensor wires and 110 VAC power to the analyzer as shown on the wiring diagram. Connect the Cleaner
Relay to the solenoid and connect the 4-20 mA Output(s) and Alarm Relay to the Control System, (PLC or
DCS). The HYDRA is then ready to use.
2.2.1 Spray Cleaner
The Spray Cleaner uses compressed air to create turbulence around the electrodes which removes dirt
and films from the measurement surfaces. Depending on the process being measured the cleaner
should be actuated for 15-30 seconds every 0.25 -2 hour period. The spray cleaner connection is a ¼”
compression fitting and requires between 25-75 psi air pressure. The air supply is controlled with a user
supplied solenoid valve through Relay 1 in the C-22 analyzer. The solenoid valve should be a 110 AC
powered, <10 watt device. Wire the solenoid to Relay 1 as described in Section 2.4.4 below.
If no air supply is available use the ECD Model AC10 Air Blast Spray Cleaner compressor. The AC10 uses
redundant intake air filters and redundant fuses on both the relays and the compressor. A highly reliable
high current contactor assures years of trouble free service. The 115 VAC 3.0 Amp or 220 VAC 1.3 Amp
Air Compressor is housed in a rugged, corrosion resistant, hot compression molded, fiberglass
reinforced, polyester enclosure with a stainless steel piano hinge to secure the cover to the base. The
AC10 can be wall mounted or use the optional 2” handrail mounting system that uses stainless steel
support rails with two 2” galvanized pipe clamps.
### NEVER SUPPORT THE HYDRA SENSOR BY THE CABLE, IRREPAIRABLE DAMAGE WILL OCCUR ###
2.2.2 Immersion /Support Tube
Feed the cable and compressed air line through the immersion/support tube (not supplied). Connect a
support tube to the 1 ¼” MNPT thread at the rear of the sensor. The Hydra sensor weighs approximately
5.3 lbs. The support tube must be able to support the weight of the HYDRA sensor in the user’s
installation, whether vertical or angled. The recommended material for the immersion tube is 1.5”
Schedule 80 PVC pipe with a reducer fitting to 1 ¼” FNPT.