Datasheet

58
Series PF2D
Specific Product Precautions 1
Be sure to read before handling.
Refer to page 57 for safety instructions and precautions.
Design and Selection
Warning
Mounting
1. Monitor the flow direction of the fluid.
Install and connect piping so that fluid flows in the direction of
the arrow indicated on the body.
2. Remove dirt and dust from inside of the
piping by means of air blow, before attaching
to the switch.
3. Do not drop or bump.
Do not drop, bump, or apply excessive impacts (490 m/s
2
) while
handling. Although the external body of a switch (switch case)
may not be damaged, the switch inside could be damaged and
cause a malfunction.
4. Hold the body of the switch when handling.
The tensile strength of the cord is 49N and applying a greater
pulling force than this can cause a malfunction. When handling,
hold the body of the switch.
5. Do not use until you can verify that equip-
ment can operate properly.
Following mounting, repair, or retrofit, verify correct mounting by
conducting suitable function and leakage tests after piping and
power connections have been made.
6. Never mount a switch in a place that will be
used as a step stool during piping.
7. Be sure to allow straight pipe length that is
minimum 8 times the port size upstream and
downstream of the switch piping.
When abruptly reducing the size of piping or when there is a
restriction such as a valve on the inlet side, the pressure
distribution in the piping changes and makes accurate
measurement impossible. Therefore, flow restriction measures
such as these should be implemented on the outlet side of the
switch.
When used with the outlet side open, be careful of the
cavitation that is prone to occur.
1. Operate the switch only within the specified
voltage.
Use of the switch outside of the specified voltage range can
cause not only a malfunction and damage to the switch, but it
can also cause electrocution and fire.
2. Do not exceed the maximum allowable load
specification.
A load exceeding the maximum load specification can cause
damage to the switch.
3. Do not use a load that generates a surge
voltage.
Although the circuit at the output side of the switch is surge
protected, damage may still occur if a voltage surge is applied
repeatedly. When a load which generates a surge, such as
from a relay or solenoid valve is directly driven, use a switch
with a built-in surge absorbing element.
4. Be sure to verify the applicable fluid.
The switches do not have an explosion proof rating. To prevent
possible fire hazard, do not use with flammable gases or fluids.
5. Monitor the internal voltage drop of the switch.
When operating below the specified voltage, it is possible that
the load may be ineffective even though the pressure switch
function is normal. Therefore, the formula below should be
satisfied after confirming the minimum operating voltage of the
load.
6. Use the switch within the specified flow rate
measurement and operating pressure.
Operating beyond the specified flow rate and operating
pressure can damage the switch. Especially avoid the
application of pressure through a water hammer, which is
above the specification.
<Examples of pressure reduction measures>
a) Use a device such as a water hammer relief valve to slow the
valve’s closing speed.
b) Absorb impact pressure by using an accumulator or elastic
piping material such as a rubber hose.
c) Keep the piping length as short as possible.
7. Design the system so that the fluid always
fills the detection passage.
Especially for vertical mounting, introduce the fluid from the
bottom to the top.
8. Operate within the flow rate measurement
range.
If operated outside of the flow rate measurement range, the
Karman vortex will not be generated and normal measurement
will not be possible.
9. Never use inflammable fluids and/or permea-
ble fluids.
They may cause a fire, an explosion or corrosion.
∗Refer to the MSDA (material safety data sheet) when using
chemicals.
Supply
voltage
– >
Internal voltage
drop of switch
Minimum operating
voltage of load
Warning
Caution
Design and Selection
1. Data from the flow switch is stored even after
the power supply is off.
The input data is stored in EEPROM so that the data will not be
lost after the flow switch is turned off. (The data can be rewritten
for up to one million times, and stored for up to 20 years.)
2. Accumulated flow rate is reset when it is
turned OFF.