Mitsubishi Electric QAHV-N560YA-HPB, Service Handbook

Page: 49 / 176

[
II
Restrictions ]
- 42 -
HWE1517A GB
2. System using a two-way valve
Notes on pump selection and connection
Select a pump in the same way as for a system with a three-way valve.
Notes on two-way valve selection and connection
• Use a valve that is capable of adjusting the flow rate with a 0 to 10 V input.
• Calculate the Cv value and select a valve that supports an appropriate rate.
• Select a valve of which the ratio of the maximum flow rate and the minimum flow rate will be at least 1:10.
• There are various kinds of two-way valve (such as ball valve, butterfly valve, and globe valve), and there are
valves suitable for flow rate adjustment and valves that are not suitable for flow rate adjustment. Therefore be
sure to select a two-way valve of a kind capable of precisely controlling the flow rate, such as a butterfly valve or
globe valve.
• Place the two-way valve downstream of the pump.
• Carefully read the instruction manual and use the two-way valve in accordance with the usage procedures.
3. System using an inverter
Notes on pump selection and connection
Select a pump in basically the same way as for a system with a three-way valve or two-way valve.
• Select a pump that can be used also at a low frequency (6 Hz or less).
(The motor may be seized depending on the pump selected as this control is performed at a low frequency.)
• Select a pump of which flow rate at 100% output is between 20 to 30 ℓ/min.
Notes on inverter selection and connection
• The inverter needs to be able to adjust output with a 0 to 10 input.
• Select an inverter that will not cause the seizing of the motor.
• Configure the settings so that the flow rate on the secondary side will become 0 ℓ/min when the unit is not
operating.
• Carefully read the instruction manual and use the inverter in accordance with the usage procedures.
Overview of system
This system has a pump provided at the outlet of the
tank and a two-way valve provided downstream of
the pump, and adjusts the flow rate by controlling the
opening and closing of the two-way valve.
Flow rate
output device
Flow rate
adjustment device
Pump Two-way valve
Wiring
connection
places 1-3 of CN512 of
control board
(ON/OFF output)
Sub box
terminal block
No. 10, 11, 12
ON/OFF signal
0 to 10 V output
Two-way
valve Pump
Overview of system
This system has a pump provided at the outlet
of the tank and an inverter connected to the
pump, and adjusts the flow rate by changing
the frequency of the inverter.
Flow rate
output
device
Flow rate
adjustment
device
Pump Inverter
Wiring
connection
places
-
Sub box
terminal block
No. 10, 11, 12
0 to 10 V output
Pump
Inverter
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