YOKOGAWA PH450G

<3. Piping and Wiring>
3-3
IM 12B07W01-04EN 1st Edition : Nov. 11, 2016-00
3.2 Wiring
The following six electrical connections must be provided to the chemical cleaning pH measuring
system. Note that slightly different wiring procedures are used depending on the system
conguration, either the intelligent two-wire pH transmitter system or the intelligent four-wire pH
converter system.
(1) Connection for pH sensor cable
Connect the pH sensor cable assembled in the PH8HS3 holder with the terminals of the
PH450G pH/ORP converter or 2-wire analyzers’ (FLXA202/FLXA212) terminals.
NOTE
The standard pH sensor cable is 3 m or 20 m long. If the PH8HS3 holder is located away from
the PH8SM3 operating unit at a distance greater than either of these lengths, it may become
necessary for you to use the PH8TBG/WTB10 terminal box through which this connection is
made.
(2) Connection for DETECT UPPER LIMIT signal (signal for detecting the upper limit of the
sensor holder’s position)
Connect the terminals of the PH8HS3 holder with the terminals of the control box in the
PH8SM3 operating unit.
(3) Connection for power supply and ground
For the intelligent four-wire pH converter system, set up power-supply connections with the
power supply box in the PH8SM3 operating unit. For the two-wire pH transmitter system, set
up power-supply connections with the terminals of the control box in the PH8SM3 operating
unit, Supply power to the PH201G distributor.
Note: The methods of power-supply connection (either a plug or terminal connection) differ
depending on the specications of the PH201G distributor. For further details, see the
IM19B01E04-02E user’s manual.
(4) Connection for pH signal
For the intelligent four-wire pH converter system, set up wiring for signal output on the
PH450G pH/ORP converter.
For the two-wire pH transmitter system, set up connection (for a transmission signal)
between the PH202G intelligent pH transmitter and the PH201G distributor, with the wiring
for an output signal provided to the PH201G distributor.
(5) Connection for contact output of CYLINDER FAIL signal
Set up this connection with the control box in the PH8HS3 operating unit.
(6) Connection for contact input of WASH (cleaning) signal
This connection is essential for the two-wire pH transmitter system. Set up the connection
between the control box and the PH201G distributor.
Note: For the four-wire pH converter system, connect the control box with the PH450G pH /
ORP converter (this connection is already made before shipment).