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I have been asked to quote on wiring five Daikin VRV systems each with 7 to 8 indoor units 18-20Kw cooling each. Though I have been working on Daikin for quite a while this is my first VRV system. What I would like to know is, does the electrical feed for each of the indoor fans have to go back to the outdoor unit or is there another way to wire them?
each unit has a power supplyQuote:
Originally Posted by anracau
then the units are daisy chained to each other including the bs box aswell. linking then back to the condenser
So each indoor unit has an independent power supply & only the screened interconnects go back to the oputdoor unit? What is the bs box?
yep that is correct, bs box is where the 3 pipes go in and only 2 come out to go to the indoor unitQuote:
Originally Posted by anracau
Bs boxes are located next to each indoor unit and contain a solonoid valve which opens and lets through refrigerant (to heat or cool) depending on what the indoor unit is asking for.
Hello Anracau,
The wiring is quite straight forward on the VRV system, and can be broken down into power supply wiring, basic VRV control wiring (must be present on all VRV systems) and controls wiring (depends on how you want to control the VRV systems and if you have any centralised controls)
Power Supply Wiring
On the outdoor unit you need a 3 phase + neutral power supply. Make sure the neutral is wired permanently to the unit (i.e. not switched through the isolator). If you apply just the 3 phase without the neutral connected, the main outdoor PCB may go “BANG”. Always use a 3 pole MCB, don’t use individual fuses or MCBs.
On the indoor units you can run a 230V AC ring main, with switch spurs to each indoor unit and BS Box if its is a heat recovery system. (3 or 5 amps depending on the size of the indoor unit). I would recommend a fused spur ( not switched spur) for the wall and floor mounted units. This is because if the end user switched off the spur to one indoor unit then the entire system will shutdown (this is a safety feature). All and floor mounted units are most accessible to the end users.
VRV Basic Wiring
You should get a wiring diagram for the systems you are installing from the supplier. The type of cable you need if 2 core non-screened 0.75mm² as specified by Daikin. You can help yourself by using 2 colours (white and black) for the different wiring loops. E.g. use the black cable between the outdoor units and the BS Boxes. Use the white cable between the BS Box and the indoor units. Use the black cables between the indoor units and the remote controllers. This should help to reduce any wiring errors. The simplest way to remember the basic wiring is to remember that the wiring follows exactly the field piping. All the BS Boxes physically piped to one outdoor unit must also be wired to the outdoor unit. All indoor units piped to a BS Box must be wired to that BS Box.
There is a minimum cable separation distance between the control cables and power cables. E.g. say the power cable was consuming 10amps, the control cables if running alongside should be at least 300mm away. There is table in the installation manual.
Control Wiring
The type of cable is the same as above. From the centralised controls you will need to run cables to the outdoor units.
In case you have group control, you may need to daisy chain between the remote controller and several indoor units.
There are examples of control and power wiring in the installation manuals. Spend an hour to read the manual and you won’t have a problem.
Regards
Obi Wan
Thanks for the help.
The Diakin equipment supplier should supply a detailed wiring diagram as part of the quote/install package.
Ask to have sight of it.
dear sir,
i have a query i am new on vrv's and i have a question ,
my client have two high wall units and wants to replace them with two casette units of the same 28.000 btu's is that possible ?( the control circuit board is the same as specified on the circuitdiagram).there is no info on the indoor units. actually on the outdoor is saying 410 a but how can i know the casette type of what refrigerant they are? in the old days you can actually see that on the diaphram of the txv but these does have the same info ?does a 410a indoor means only that refrigerant?
Do you have model no. on casete units!
hi, m just browsing thru this post on VRV wiring, just wanna say that the information from this post is helpful.
Quote:
Originally Posted by steve bajada
All indoor units are compatible with the outdoor unit if the system is VRV.So i don't need models to confirm it.Just change it and that's it.There should be no problem as you won't do any different kw .This is what matter to keep the system in balance.Indoor units design doesn't matter just kw.:D
Why cant the control cable be screened??
Quote:
Originally Posted by SUBCONTRACTOR
Only 410a vrv indoor units can be conected to a 410a vrv out door unit this is easily identified by the outdoor/indoor model numbersQuote:
Originally Posted by anracau
Outdoor example REYQ10P8Y1
R = Outdoor unit
EY= Heat Recovery (3 pipe) / XY= Heat Pump (2 pipe) / X Cooling only (2 pipe)
Q = 410A (refrigerant type)
10 = Capacity in horse power (1 hp = a capacity index of 25)
P7/8 = Series of unit (VRV III) / M7/8 = VRVII
Y1 = 3 phase 415v
Indoor example FXSQ50PV1
FX = IVRV ndoor unit
S = Ducted indoor / A = Wall Mount / ......
Q = 410A (refrigerant type)
P = Series of unit
V1 = Single phase 230v