General Assist Technical Reference
IPM PCB Service Parts
Replacement, compatibility and ordering guidance for K18RE and K18RD inverter assemblies
Based on Service Bulletin RAC-0087, issued 29 November 2018
The IPM PCB service parts were changed following a supplier change. The replacement requirements are different depending on whether the existing assembly is a K10AY type or a K11BY type.
Important: K18RE replacement parts are not always a direct like-for-like change. Confirm the outdoor unit model and whether it uses a U chassis or Y chassis before carrying out the replacement procedure.
1. What changed?
| Existing type | Replacement type | Compatibility | Action |
|---|---|---|---|
| K10AY | K18RE | Specifications of the old and new parts are different. | Follow the applicable U-chassis or Y-chassis replacement procedure. |
| K11BY | K18RD | Old and new parts are compatible. | The replacement can be carried out as a direct exchange. The bulletin states there is no separate replacement manual for this type. |
2. Parts ordering
General rule: Order using the old part number. Once old stock is exhausted, the replacement part will be supplied automatically.
Exception - old part 9709680780: This K18RE application was split into two replacement part numbers, 9709682982 and 9709682890. For these units, the correct new part number must be selected according to the chassis/application.
For Taiwan models identified in the bulletin, changeover to the new parts became available after February 2019.
3. K10AY to K18RE part conversion
| Old part no. | Old description | New part no. | New description | Chassis |
|---|---|---|---|---|
| 9709680780 | K10AY-1400HUE-TR0-SV | 9709682982 / 9709682890 | K18RE-1800HUE-TR0-SV | U / Y - confirm model |
| 9709680858 | K10AY-1500HUE-TR0-SV | 9709682906 | K18RE-1801HUE-TR0-SV | Y |
| 9709680902 | K10AY-1501HUE-TR0-SV | 9709682913 | K18RE-1802HUE-TR0-SV | Y |
| 9709681282 | K10AY-1502HUE-TR0-SV | 9709682920 | K18RE-1803HUE-TR0-SV | Y |
| 9709681268 | K10AY-1600HUE-TR0-SV | 9709682937 | K18RE-1804HUE-TR0-SV | Y |
| 9709681527 | K10AY-1601HUE-TR0-SV | 9709682944 | K18RE-1805HUE-TR0-SV | Y |
| 9709682043 | K10AY-160AHUE-TR0-SV | 9709682951 | K18RE-1806HUE-TR0-SV | U |
| 9709682029 | K10AY-1700HUE-TR0-SV | 9709682968 | K18RE-1807HUE-TR0-SV | Y |
| 9709682036 | K10AY-1701HUE-TR0-SV | 9709682975 | K18RE-1808HUE-TR0-SV | Y |
Model verification: The bulletin contains an extensive model-by-model list. Always confirm the exact outdoor model against the applicable parts information before ordering, particularly for part number 9709680780 where the replacement differs by application/chassis.
4. K11BY to K18RD part conversion
| Old part no. | Old description | New part no. | New description |
|---|---|---|---|
| 9709907092 | K11BY-110GHUE-C1 | 9709682685 | K18RD-1800HUE-C1-SV |
| 9709907160 | K11BY-1202HUE-C1 | 9709682692 | K18RD-1801HUE-C1-SV |
| 9709907177 | K11BY-1203HUE-C1 | 9709682708 | K18RD-1802HUE-C1-SV |
| 9709907184 | K11BY-1204HUE-C1 | 9709682715 | K18RD-1803HUE-C1-SV |
| 9709680414 | K11BY-1300HUE-C1-SV | 9709682722 | K18RD-1804HUE-C1-SV |
| 9709680421 | K11BY-1301HUE-C1-SV | 9709682739 | K18RD-1805HUE-C1-SV |
| 9709907009 | K11BY-1100HUE-C1 | 9709682746 | K18RD-1806HUE-C1-SV |
| 9709907016 | K11BY-1101HUE-C1 | 9709682753 | K18RD-1807HUE-C1-SV |
| 9709907030 | K11BY-1103HUE-C1 | 9709682760 | K18RD-1808HUE-C1-SV |
| 9709907047 | K11BY-1104HUE-C1 | 9709682777 | K18RD-1809HUE-C1-SV |
| 9709907061 | K11BY-1107HUE-C1 | 9709682784 | K18RD-180AHUE-C1-SV |
| 9709907078 | K11BY-110AHUE-C1 | 9709682791 | K18RD-180BHUE-C1-SV |
| 9709907085 | K11BY-110FHUE-C1 | 9709682807 | K18RD-180CHUE-C1-SV |
| 9709907108 | K11BY-110HHUE-C1 | 9709682814 | K18RD-180DHUE-C1-SV |
| 9709907115 | K11BY-110KHUE-C1 | 9709682821 | K18RD-180EHUE-C1-SV |
| 9709907146 | K11BY-1200HUE-C1 | 9709682838 | K18RD-180FHUE-C1-SV |
| 9709907153 | K11BY-1201HUE-C1 | 9709682845 | K18RD-180GHUE-C1-SV |
| 9709681961 | K11BY-1600HUE-C1-SV | 9709682852 | K18RD-180HHUE-C1-SV |
| 9709681916 | K11BY-1601HUE-C1-SV | 9709682869 | K18RD-180KHUE-C1-SV |
| 9709681923 | K11BY-1602HUE-C1-SV | 9709682876 | K18RD-180LHUE-C1-SV |
| 9709681930 | K11BY-1603HUE-C1-SV | 9709682883 | K18RD-180MHUE-C1-SV |
| 9709907023 / 9709907122 / 9709907139 | Selected K11BY applications | No change | No change |
5. K18RE replacement procedure
Electrical safety: Isolate the outdoor unit from the mains supply and allow the inverter DC bus to discharge before accessing or replacing the inverter assembly. Confirm the absence of hazardous voltage using appropriate test equipment.
U chassis
- Remove the initial 6 connectors from the inverter/control section.
- Remove the 5 screws, turn the control box upside down and temporarily secure it with one screw.
- Remove the remaining 9 connectors.
- Remove the 6 inverter assembly screws. The bulletin identifies these as fine-thread screws and notes that a short Phillips screwdriver may be required for access.
- Remove the old inverter assembly. If it is stuck, carefully release it at the gap as shown in the service procedure.
- Remove the ACTPM and the two cables from the old inverter assembly. Wipe the old heat paste from the back of the ACTPM.
- Fit the ACTPM and the two cables to the new inverter assembly. Apply the supplied heat paste to the back of the ACTPM, then connect the four specified connectors.
- Install the new inverter assembly, ensuring cables and connectors are not pinched.
- Tighten the 6 inverter assembly screws.
- Reconnect the 9 connectors.
- Return the control box to its correct position and secure it.
- Reconnect the initial 6 connectors.
Y chassis
- Remove the 15 connectors from the inverter assembly.
- Cut the cable tie securing the black/white CN21 wiring, where fitted.
- Remove the 6 inverter assembly screws. The bulletin identifies these as fine-thread screws and notes that a short Phillips screwdriver may be required.
- Remove the old inverter assembly. Take care around the heat-sink cover, coil and capacitors.
- Remove the ACTPM from the old inverter assembly and wipe the old heat paste from the back.
- Fit the ACTPM to the new inverter assembly, reconnect the two ACTPM connectors, and apply the supplied heat paste to the back of the ACTPM.
- Install the new inverter assembly, making sure cables and connectors are not pinched.
- Tighten the 6 inverter assembly screws.
- Reconnect the 15 connectors.
- Secure the black/white CN21 wiring with the supplied cable tie where required.
6. Replacement kit contents
| Item | Quantity / note |
|---|---|
| Inverter assembly | 1 |
| Heat paste | 1 - required on the rear of the ACTPM during K18RE replacement |
| Cable tie | 1 - used for the Y chassis CN21 wiring where applicable |
| Installation manual | 1 |
Service tip: Before disconnecting the existing inverter assembly, photograph the connector positions and wiring route. During reassembly, compare all connector locations and cable routing with the original configuration and confirm that no wiring is trapped beneath the inverter assembly or control box.
Source: Service Bulletin RAC-0087 - IPM PCB Service Parts, issued 29 November 2018. Always confirm the applicable service documentation and part information for the exact model before replacement.