Brand: HITACHI
Category: Air Conditioner
Document Type: Manual
Language: EN
Manual for RAC-DJ18PHAE
Uploaded: Nov. 21, 2025, 6:28 p.m.
The manual provides technical information for service personnel. It includes specifications, construction and dimensional diagrams, wiring diagrams, block diagrams, refrigerating cycle diagrams, disassembly/reassembly procedures, main circuit operation descriptions, service call Q&A, troubleshooting guides, and parts lists. Safety precautions for repair work and handling of semiconductors are also detailed. Specific sections cover outdoor unit installation, component specifications, and operational procedures like running the product with an outdoor unit test switch and operating the outdoor unit independently. Detailed troubleshooting charts for various error codes and conditions are provided, focusing on checking electrical parts, refrigerating cycles, and component failures.
Troubleshooting and error codes
| LD301 Blinking | Possible Malfunctioning Part | Troubleshooting Steps | Corrective Action | ||
|---|---|---|---|---|---|
| 13 times | EEPROM reading error | Check the F cable connection (half insertion, thin cable, erroneous connection between terminal boards 1, 2, and 3, or other abnormalities). | Replace the outdoor electrical parts (in the case of an abnormality in the microcomputer or EEPROM). | ||
| 9 times | Communication error | Normal Blinks 3 times | Correct the F cable connection. | ||
| Once | Reset stopped | Check that the indoor timer lamp blinks. | Check the indoor electrical parts. (Check the temperature fuse in the terminal board.) | ||
| Once | Reset stopped | Yes | Blinks 12 times | Replace the outdoor electrical parts (in the case of an abnormality in the communication circuit). | |
| Once | Reset stopped | No | Electrical parts abnormality | If the LD301 is on, it is performing cooling or heating. If the LD301 is on 2 seconds and off 0.3 seconds, the product is running with a heavy load (does not constitute a failure). If LD301 is blinking each 0.25 second, check the blinking number carefully. | Replace the outdoor electrical parts (in the case of an abnormality in the communication circuit). |
| Other | Abnormality other than compressor stoppage | Identify the failure location. | Correct the abnormal location. | ||
| Yes | If the indoor unit is either of the following states, it will blink once: lonmist in progress, 2 hours before the ON timer. | Turn the power back on, run the product either by remote control or by using the forcible cooling switch, and check the blinking frequency of the LD301. | Replace the outdoor electrical parts (in the case of an abnormality in the reset circuit or microcomputer). | ||
| No | Electrical parts abnormality | Blinking once | Replace the outdoor electrical parts (in the case of an abnormality in the voltage detection circuit or current detection circuit). | ||
| Yes | Is there 230V AC between terminal boards L and N? | Ensure the power supply. | Correct the power supply. | ||
| Yes | Normal | Breaker activated | Check for electrical leakage. After that, turn on the breaker and make a double-check. | ||
| Yes | Normal | Breaker normal | Check the indoor electrical parts. (It may have a power relay abnormality, communication error or something similar.) | ||
| Yes | Is the 15/25 A fuse normal? | Abnormal | If the 15/25 A fuse is blown out, it may have caused another part to go out of order. (Main parts: varistor, diode stack, IPM, smoothing capacitor.) | Replace the outdoor electrical parts. | |
| Yes | Is the fan motor normal? Check fan motor refer to the DC fan motor control circuit. | Abnormal | Is the 2 A fuse blown out? | Check the reversing valve refer to the circuit of reversing valve drive circuit. | Replace the outdoor electrical parts (in the case of an abnormality in the power circuit). |
| Yes | Normal | Reversing valve normal | Replace the outdoor electrical parts (in the case of an abnormality in the power circuit). | ||
| Abnormal | The LD301 will not go on and the power circuit is normal. | Replace the outdoor electrical parts in fan motor drive circuit or fan motor. | |||
| Abnormal | The LD301 will not go on and the power circuit is normal. | Replace the outdoor electrical parts (in the case of an abnormality in the microcomputer or LED). |