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8. SYSTEM DESIGN GUIDE
WR2-Series-575V
e) Installation
Note the following for installing the circulating water flow rate control system.
1. Make sure that water circuit components necessary to build a circulating water flow rate control system are in place.
See Figure c)-1 and Table c)-1.
When a system includes multiple heat-source units, each unit requires a water flow rate control valve.
2. Connect all wirings (power-supply, signal, etc.) required by the circulating water flow rate control system.
See Figure c)-1 and Table c)-2.
3. Check the circulating water flow rate control system (including the heat-source unit) for proper operation.
4. Check that the circulating water supplied to the heat-source unit is within the operating range.
Make sure the inlet water temperature is within the operating range.
Make sure the water strainer is not clogged.
Make sure the circulating water flow rate is within the operating range in both the single-heat-source-unit systems or
in the multiple-heat-source-unit systems and both during Thermo-OFF and in operation.
When using a single pump for multiple heat-source units in multiple systems, make sure that the flow rate of the
circulating water supplied to each unit is within the operating range regardless of the ON/OFF status of the
heat-source units in the system.
To check for proper operation of water flow rate control valve and to check that the circulating water flow rate is within
the operating range, the use of device that outputs a voltage between 0 VDC and 10 VDC is recommended.
5. Check the system for the following items to use the circulating water control system in the normal operating range.
Management of supply water flow rate that takes strainer clogging and other possible problems that can occur during
operation into consideration.
Adjustment of water-quality during operation
Measures against possible problems with the water-circuit system
(Examples: Water outage, circulating water flow rate outside the specification range, clogged strainer, air in the
circulation system, water pump failure, water flow rate control valve problem, pump interlock failure, etc.)
f) Expansion function for the management of circulating water flow rate
Making the following settings can reduce the power required to operate the circulating water pump in the water circuit
system. (Note that doing so may delay the start of heat-source units by a few minutes.)
Switch
Function
Operation according to the switch setting
Switch setting timing Unit (Note 2)
OFF (LED3: Unlit)
ON (LED3: Lit)
SW4
1-10
[0: OFF; 1: ON]
(Note 1)
SW6-10:
ON
No. 901 1010000111
Changes
signal output
when all
heat-source
units
(OC/OS)
go into
Thermo-OFF
Water flow rate
control valve
remains open when
all heat-source
units (OC/OS) go
into Thermo-OFF.
(Minimum water
flow rate) [Default]
Water flow rate
control valves will
close when all
heat-source units
(OC/OS) go into
Thermo-OFF.
After power on
and while the
compressor is
stopped
C
SW4
1-10
[0: OFF; 1: ON]
(Note 1)
SW6-10:
ON
No. 917 1010100111
Pump
operation ON
signal
Signals are output
when heat-source
units go into Ther
-
mo-OFF. [Default]
Signals are output
when Cooling/Heat
-
ing operation signals
are received from the
controller.
After power on
and while the
compressor is
stopped
C
(Note 1) To switch between the ON/OFF settings, first set SW6-10 to ON, then set SW4, and finally press and hold SWP1 for
two seconds or longer to reflect the change.
LED3 will be lit when the switch is set to ON, and LED3 will be unlit when the switch is set to OFF.
Check the LED3 indicator status to make sure the setting is set as intended.
The switch needs to be re-set at the replacement of the control board.
Note the settings on the electrical wiring diagram label on the control box.
(Note 2) A: Requires the switch on OC to be set.
B: Requires the switches on both OC and OS to be set to the same setting.
C: Requires the switches on both OC and OS to be set.
D: Requires the switches on either OC or OS to be set.
(Note 3) To use the functions above, be sure to set the switches in the following combinations.
· Set SW4 (901) to OFF and SW4 (917) to ON to keep the pumps on all heat-source units (OC/OS) to operate during
Thermo-OFF and to keep the water flow rate control valve open.
· Set SW4 (901) to ON and SW4 (917) to OFF to stop the pumps on all heat-source units (OC/OS) during Thermo-OFF
and to close the water flow rate control valve.
0000006382.BOOK 81 ページ ２０２１年７月１９日 月曜日 午後４時１４分
