Air conditioning system can be installed to standards or installed poorly. Up to standards installation is also a safe installation. It requires specialist training, background knowledge, specialist tooling, skills, time, some sort of a warranty, safety equipment, transportation and the signature of the installer on the commissioning sheet. This sort of know-how comes with the price tag.
Mostly in an attempt to avoid the cost of the professional installers many end-users prefer to install the system as a DIY job. There are multiple problems with this sort of installation. The following is a procedure description of the prohibited installation technique of the air conditioning system. It is not a training or manual, it is illegal, stupid and dangerous to re-enact any of this. As for the accuracy of this procedure description, the description is totally fictional and has no connection to real-life at all. Burn after reading.
We assume the power supply is not a problem in this case, maybe the system you install has an indoor plug and the outdoor is powered from inside to outside, so you can run it off your spare 16A circuit breaker in your distribution board.
Assuming the installer decided to overlook the safety procedures we still have a fundamental refrigeration problem to resolve. If this issue is not addressed during installation the system is very likely to suffer performance issues right from the start of the exploitation, system will not be able to achieve rated output, the system will pull more current than the components of the system are rated for, short-cycling will occur, fault of the system is inevitable. It is not going to be a small job to rectify this type of breakdown. To avoid these symptoms in a first place the refrigeration loop must remain uncontaminated of the air and water vapour that is present is the coils and pipework at the time of the installation. Professionals use a specialist tool called a vacuum pump. It is used to pump out any remaining pressure testing/drying gas, or in DIY install case air, from the pipework and coil(s). Not only pump out air and vapour but to create a vacuum in the system, only then the loop is considered clean and is ready to circulate the refrigerant. This vacuuming procedure is not a peculiarity of the installation, it is consistent throughout the manufacturing process of the air conditioning unit.
So how do you get any contaminants out of the pipework in this sort of the setup. The system will not last long unless this is done. This method works on the systems that are designed with normally open valves. So on the indoor unit power off(0V) all valves open, if any fitted at all. Most manufacturers use this technology as standard.
Firstly you will need goggles and gloves to protect your self. The method where the trick is to hang the units, pipe up the indoor unit. On the outdoor unit prepare both ends of the pipework but only connect the liquid pipe to the outdoor unit. The liquid line is always the thinner one, gas side is always the thicker one. After that be prepared to quickly pipe up the suction pipe, the last remaining connection, but before you do, you must open the discharge port, yes, the one you already piped up. So the gas that is under the pressure in the condensing unit would naturally push from the condensing unit through the liquid pipe, through the indoor coil and out the suction pipe, the one that is not piped up yet. On its way through the loop, the refrigerant gas will push out any air and vapour remaining in the pipework and coil. You only will need to open the valve on the outdoor unit connection port for a few seconds. The scope of this procedure is to get the vapour out of the pipe by the displacing the air in the pipe with a refrigerant gas of the system, which is in a vapour state in this part of the cycle. The gas must have some amount of acceleration and mass flow, but not too much, just enough to push the air out the open end of the pipework. You cant see the air coming out the pipe but if you to block the open pipe with your hand you would feel the pressure building up in the pipe, but don’t do that. If you see any vapour, it will be the refrigerant vapour and you can presume there is nothing but refrigerant in the pipework. Close the liquid line connection port shutoff valve. Now you should swiftly pipe up the last connection and finish the loop.