Electro-Chemical Devices (ECD) HYDRA Ammonium - Manual (Page 15)

HYDRA NH
4
+ -N Page 7
the top of the Channel 2 input card. (See diagram in Section 7.3) Then connect a shielded 22 gauge
twisted pair communication cable to Terminal #2 (+24V) on the PS2 power supply board and Terminal
#1 of the 4-20 mA 1 connector.
If a second mA output is supplied connect it in the same manner, jumper Terminal #1 of the PS2 board
to Terminal #2 of the 4-20 mA 2 output terminal strip then connect the two wire communication cable
to PS2 Terminal #2 and mA 2 Terminal #1.
If the 4-20 mA loop is powered from an external source then simply connect a shielded 22 gauge twisted
pair communication wire to Terminals #1 and #2 of the 4-20 mA terminal on the Channel 2 input card.
The standard Hydra C-22 is configured with the NH4 + -N on mA 1 and pH on mA 2.
2.4.4 Wiring, Contact Relay Outputs
The standard configuration has two SPDT 230V 5 A relays that can be wired either normally open (NO)
or normally closed (NC). The default configuration is set to use the relays as normally open. Relay 1
actuates the solenoid for the air blast spray cleaner and Relay 2 is an NH
4
+
-N alarm relay, either a High or
Low Alarm.
Relay 1
Connect the Line terminal of the 110VAC power to the C (common) terminal of Relay 1. Connect the
Cleaner solenoid wires to the neutral terminal of the 110 VAC power and the NO (normally open)
terminal of Relay 1. (See Section 7.3)
Relay 2
Wire Relay 2 as a NO relay. Relay 2 is an alarm relay and should be connected to the Control System or
an external alarm.
Do not run the cable through the same cable gland fitting as the electrodes or the 4-20 mA signals.
The MASTER configuration has (4) SPDT 230V 5A relays that are wired as normally open (NO) relays.
Relay 1
Wire Relay 1 as a NO relay. Relay 1 is an alarm relay and should be connected to the Control System or
an external alarm.
Do not run the cable through the same cable gland fitting as the electrodes or the 4-20 mA signals.
Relays 2 (NO), 3 (NO), 4 (NO)
Connect to AC10 per wiring diagram in AC10 Air Blast Spray Cleaner
The SLAVE configuration has (2) SPDT 230V 5 A relays that are wired as normally open (NO) relays.
Relays 1, 2
Wire Relays 1 and 2 as a NO relays. Relays 1 and 2 are alarm relays and should be connected to the
Control System or an external alarm.