Frequently Asked Questions –


Are there additional materials needed to install the control?

Yes, you will need at least three “T’s” or someway of connecting the APR Control to the system suction line, liquid line, hot gas line and the external equalizer line where necessary. In addition, isolation ball valves are required. Without the ability to isolate the APR Control from the circuit there may be NO WAY TO CHARGE OR CONDUCT SYSTEM DIAGNOSTICS.

Do I need to mount the control?

Yes, vibration resulting from the operation of the compressor could put strains on the piping and control. A simple mount to either the cabinet or a stand is all that is needed.

Is the APR Control sensitive to how it is positioned?

Yes, the APR Control can only be mounted in such a way that the Schrader/access valve is located down and the mixed gas discharge to the suction outlet up. ANY OTHER POSITION OR ORIENTATION IS UNACCEPTABLE AND WILL LEAD TO SYSTEM PROBLEMS AND LIKELY DAMAGE.

Do I have to install the APR Control inside the unit?

No, it is preferred to install the APR inside the unit housing, but it is also ideal to have access to the control. If exterior installation is preferred make sure there is limited access to the unit from the general public.

Do I have to add refrigerant to compensate for the control?

No, the chamber holds no charge.

What type of protection does the APR Control need during installation?

This is a delicate control much like a TXV or any other device added to the refrigerant system. Thus you need to provide the protection from excessive heat when soldering or brazing.

What type of Solder can I use?

We recommend Harris Products Stay-Silv 15 or equivalent 15% silver alloy for situations in which close fit-up does not exist, and where thermal expansion and service vibration are involved.

What material is the APR Control valves?

Please note that the APR Control valves that will be connected to are of stainless steel construction, but the interior of the branch connection is copper clad to allow for an easier process.

Is there a particular place or location I connect to the piping?

Yes for all three lines. The liquid line needs to be connected after the system dryer (only if the system already has one. We are looking at the filter part of the dryer to protect the desuperheater valve. When connecting the hot gas line you need to ensure no oil traps are formed at the connection or could cause the APR chamber to trap oil. Do not connect into the bottom of a horizontal hot gas line, A potential oil trap could be formed. Installation requires connection into the side or top of the horizontal line. The same is true with the suction line with one critical addition, because the velocity in the suction line is lower (than the hot gas line) the connection into it needs to be from the top (reference of 10-2 on a clock), even connecting into the side could cause some issues pertaining to oil.

Where do the bulbs and equalizer lines go?

Bulbs connected to the APR Control valves will be installed between the Tee connecting the APR to the suction line and the compressor. These bulbs must be strapped to the suction line and properly insulated. Equalizer Lines (where the APR Control has such connections) will tap into the suction line between the suction line Tee and the compressor.

Do the Bulbs need insulation?

Yes, This is as critical as any step in the installation of the APR control. The insulation needs to properly installed and completely covering the APR Control valve bulbs. The insulation needs to be adequate to protect the bulb from the ambient temperature

Does the control need to be insulated?

No, the APR Control must not be insulated as this would reduce the effectiveness of the APR Control’s operation. System heat (in the form of hot gas) is shed through the wall of the desuperheater chamber.

My unit will have to run in a low ambient condition is there anything I need to do?

The first question is what type of low ambient control do you have? If it is a modulation type of either the fan motor or some type of damper control for the air then there should be no issue. As long as we have somewhat of a steady head pressure the APR Control can operate just fine in the system. Low ambient control with simple fan cycling is less than ideal. This type of low ambient control produces significant and erratic changes in head pressure. This can cause issues with operation of the APR Control since it operates off of suction pressure. If a head master type of control on the refrigeration circuit is used then a solenoid with a pressure sensor is needed to lock out the control under low head pressure. This will allow for the system to stabilize before the control is brought into operation.