YOKOGAWA PH450G

<3. Piping and Wiring>
3-5
IM 12B07W01-04EN 1st Edition : Nov. 11, 2016-00
(3) Connection for power supply and ground
<Connection for power supply>
A power supply voltage of 100 V AC ±10%, 50/60 Hz is applied to the power supply unit of
the chemical cleaning pH measuring system.
CAUTION
Chemical Cleaning pH Measuring System has no power switch. To avoid the possible hazard of
electrical shock or damage to the instrument, always install a power switch (double-pole) in the
power line.
NOTE
The fuse (1 A) in the power supply unit is installed for the pH/ORP converter. (The pH/ORP
converter itself contains an additional power-line fuse (0.1 A)).
Use a two-core cable with an outer diameter of 9 to 12 mm for this connection. Treat both
ends of each core wire of the cable extending from the power supply so they t M-4 thread
and then connect them with terminals L1 and L2 of power supply unit.
<Connection for ground>
The control box and pH/ORP Converter of the system must be grounded with a grounding
resistance of less than 100Ω). The grounding terminal of the control box can be found in the
bottom of the control box casing. The grounding terminal of the pH/ORP Converter can be
found in the bottom of the control box casing.
(4) Connection for contact output of CYLINDER FAIL signal
PH8SM3 Chemical Cleaning System outputs a CYLINDER FAIL contact signal. This
contact signal is output to let the operator know that a failure has occurred in the upward
movement of the pneumatic cylinder of the PH8HS3 holder. The system uses the DETECT
UPPER LIMIT signal (the signal for detecting the upper limit of the sensor holder’s position)
discussed in step 2 above for this purpose.
The CYLINDER FAIL contact signal is given if the DETECT UPPER LIMIT signal is not
present even if the setting for timer T1 in the control box is reached. This connection is
applied when the above function is used. Use a two-core cable with an outer diameter of 9
to 12 mm for this connection. Treat both ends of each core wire of the cable so they t M4
threads and then connect terminals 6 and 7 of the control box with the instrument being
used, such as an annunciator. For the contact capacity and other details, see subsection
1.1.
(5) Connection for pH signal
PH450G pH/ORP Converter sends two 4 to 20 mA signal (pH, temperature) and receives
the contact input for cleaning start. Use a two-core cable with a nished outer diameter
of 9 to 12 mm for this connection. For the output signal from pH/ORP Converter, connect
the terminals “mA1 +” or “mA1 -” to those corresponding terminals at the receiving
instrument. For the second output signal, connect the terminals “mA2 +” or “mA2 -” to those
corresponding terminals at the receiving instrument.The terminal CONTACT on a pH/ORP
Converter is for connection of remote contact input. For cable shield, connect a cable to the
terminal SHLD.
CAUTION
Connect the cable shield to the grounding at pH/ORP converter.