Electro-Chemical Devices (ECD) DCA-23 - Manual (Page 11)

DCA-23 Page 5
2.2 WIRING
Electrical wiring should only be conducted by qualified personnel. See the wiring color code for the DCA-
23 in Section 8.3 below.
2.2.1 Wiring, Sensor(s)
The TRO Sensor and the PHS10 pH Sensor were connected to the T-23 transmitter at the factory, no
additional connections are necessary. Color coded connections for these sensors are shown in the wiring
diagrams in Section 8.3 or inside the cover of the T-23 analyzer.
2.2.2 Wiring, power
Attach power cable, either 110/220 VAC or 24 VDC, as shown in the diagram in Section 8.3 or inside of
the T-23 cover. Feed the cable through the gland fitting on the right hand side of the T-23. Tighten the
cable gland to provide a good seal to the cable. The instrument can be powered up at this point with no
harm to the analyzer but it is best to wait until the sensors are installed.
2.2.3 Wiring, 4-20 mA Outputs
The 4-20 mA outputs are unpowered outputs, 24V can be supplied from an external source (loop
powered), i.e. the PLC or DCS or from the optional internal PS10/11 power supply.
If the internal PS10/11 Power Supply is used, follow the wiring diagram in Section 8.3 for the particular
instrument.
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.
The standard configuration has Chlorine (TRO) on mA 1 and (optional) pH on mA 2.
2.2.4 Wiring, Contact Relay Outputs
This optional 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.
Relays 1&2
Wire Relays as a NO relay. (See diagram in Section 8.3) The Relays are alarm relays and should be
connected to the Control System or an external alarm.
Do not run the Alarm Relay cable through the same cable gland fitting as the electrodes or the 4-20 mA
signals.