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[1-3 Working with Refrigerant Piping ]
1-3
Working with Refrigerant Piping
1-3-1
Pipe Brazing
No changes have been made in the brazing procedures. Perform brazing with special care to keep foreign objects (such as oxide
scale, water, and dust) out of the refrigerant system.
Example: Inside the brazed connection
Use of no inert gas during brazing
1. Items to be strictly observed
Do not conduct refrigerant piping work outdoors if raining.
Use inert gas during brazing.
Use a brazing material (BCuP-3) that requires no flux when brazing between copper pipes or between a copper pipe and
copper coupling.
If installed refrigerant pipes are not immediately connected to the equipment, then braze and seal both ends.
2. Reasons
The new refrigerating machine oil is 10 times as hygroscopic as the conventional oil and is more likely to cause unit failure if
water infiltrates into the system.
Flux generally contains chloride. Residual flux in the refrigerant circuit will cause sludge to form.
3. Notes
Do not use commercially available antioxidants because they may cause the pipes to corrode or refrigerating machine oil to
deteriorate.
HWE13080
Use of inert gas during brazing
- 10 -
GB
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Troubleshooting
Need help?
Do you have a question about the PURY-HP72 and is the answer not in the manual?
Questions and answers
what is the set up mode for recovery, and charging of sys?
Why can control my indoor unit with centralize control
You may not be able to control your Mitsubishi Electric PURY-HP72 indoor unit with centralized control for the following reasons:
1. The power jumper connector on the outdoor unit may not be correctly set. It should be connected to CN40 on only one outdoor unit.
2. The central control switch (SW5-1) on the control board of all outdoor units must be set to "ON."
3. Address settings may not be correctly configured. The main indoor unit should be assigned the smallest address (e.g., IC00), and correct port number settings are required.
4. If using a remote controller alone, an interlock setting from the remote controller is needed.
5. Both ME and MA remote controllers cannot be connected to the same indoor unit group.
6. System controller power issues may occur if the outdoor unit fan rotates due to external forces, causing the system controller to detect an error.
7. Improper wiring or incorrect voltage at TB7 may also prevent operation.
Check each of these conditions to ensure proper centralized control.
This answer is automatically generated
Why can’t control indoor unit with centralize control and stay the MA control set up can’t. Control the mode
The Mitsubishi Electric PURY-HP72 indoor unit cannot be controlled with centralized control and the mode control setup does not function due to the following reasons:
1. Central control is not possible if the indoor/outdoor transmission line is used, even if TB7 terminals are daisy-chained.
2. Shielded cables must be used, and the connection must only be made after confirming the voltage is below 20 VDC.
3. Improper connection of the transmission line for centralized control, such as not correctly daisy-chaining terminals M1 and M2 or not short-circuiting the earth and S terminals on TB7.
4. If a power supply unit is not connected to the centralized control line, the power jumper connector must be moved from CN41 to CN40 on one outdoor unit—if this is not done, mode control will not function.
5. Overlapped indoor unit addresses or noise interference on the remote controller lines can also prevent proper control.
6. Failure to set one MA remote controller to MAIN or exceeding its capacity can result in control failure.
All these factors must be correctly configured for centralized and mode control to function properly.
This answer is automatically generated