Daikin GCU2020PXB1 Installation, Commissioning And Maintenance Manual page 99

ENG
EVD + pRack pR300T connections:
Ultracap Technology
•
via a EVD EVO external driver (fi g. 2.g) or integrated in PRK30TD***
models, in both cases using fi eldbus serial.
EVD + pRack pR300T connections: via filedbus
24 Vac 230 Vac
35 VA
TRADRFE240
(dedicated)
3
J2 6 FBus2
6.16.2 Unit of measure
pRack PR300T can manage two units of measure, the international
system and Imperial.
Note: the temperature and pressure units of measure can be
changed from °C, barg to °F, psig only during start-up; mixed
confi gurations are not allowed, for example °F and barg.
6.16.3 Sign of life
pRack PR300T can manage a digital output acting as a sign of life,
activated when pRack PR300T is powered up. This output remains active
while the controller is working correctly and highlights any hardware
faults. The Signal can be confi gured in main menu branch B.a.c.
6.16.4 Liquid non-return
pRack PR300T can manage a digital output with the meaning of liquid
non-return. This normally active output is deactivated when all the
compressors are off and no compressor can be started due to alarms or
time settings, despite the control request, or when the unit is OFF. As soon
as at least one compressor is enabled to start, the output is deactivated,
allowing management of a liquid non-return valve. The function can be
confi gured in main menu branch C.a.g/C.b.g.
Copyright HPL March 2021
pRack PR300T +0300018EN rel. 1.5 - 02.05.2017
230 Vac
24 Vac
35 VA
TRADRFE240
2 AT
(dedicated)
1 3 2 4
EVD
evolution
GND Tx/Rx
Fig. 6.au
shield
2 AT
1 3 2 4
Ultracap Technology
Tx/Rx
GND
Fig. 6.av
6.16.5 Parallel compressor
pRack pR300T can enable a line of compressors in parallel to the medium
temperature suction line upstream of the RPRV valve using a dedicated
board, and starting from version 3.3.0 this board can be enabled via
pLAN. If managing a single parallel compressor (again starting from
version 3.3.0), the main control board can be used, i.e. without requiring
a dedicated board.
AUX
COMP
FLASH
This function is confi gured in branch COMPRESSORS
compress.
Compressors
a. Line 1
b. Line 2
c. Parallel compression
If the parallel compressor line is managed using an additional board (via
pLAN or connected via DI/DO):
Parallel Compr. Cca01
Enable parallel
compressor:
Control mode:
Parallel Compr. Cca01
Enable parallel
compressor:
Control mode:
in both cases, the board follows the confi guration and relative restrictions
described in the paragraphs on control 6.3 and compressors 6.4.
50
Page 99 of 179
HR1 HR1 HR2 HR2
HPV
RECEIVER
E E 2 2 V V
E E 2 2 V V
E E 2 2 V V
E E 2 2 V V
Fig. 6.aw
c.Parallel
- -
3/3
-
YES
EXTERNAL PLAN
YES
EXTERNAL I/O
P41135 Rev 03