Field Troubleshooting

05EarthGuard EG‑600 and EG‑600‑SC18LEDs and Buzzer18Common Faults18Finding an Earth Fault19Testing the EarthGuard2006CoolPro CP3021Indicators21Common Faults21Modbus Communication2207Battery Sense23LEDs23Common Faults2308Solinteg M2HT and All-In-One25Inverter Indicators25Common Inverter Faults25All-In-One Cabinet and Battery2609Support and Returns28Before You Contact AERL28Returning a Product28Change Log28Thank You for Choosing AERL29

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This guide helps installers find and fix the faults most often met in the field on AERL products. It is organised by product, then by symptom. Each table gives what you see, its likely cause, what to check and the fix.

The guide summarises. Each product's user manual is the full reference: where a table names a chapter, it is the chapter of that product's manual. Use the latest manuals and software from aerl.com.au and aerl.com.au/professionals.

Danger — isolate before you work

Only qualified people may test, open or rewire this equipment. Battery and PV circuits stay live when an inverter or controller is switched off, and a DC arc does not self-extinguish. Follow your isolation procedure, prove dead with a meter rated for the system voltage, and wear PPE.

Before You Start

• Note what the product shows before you touch anything: LEDs, display codes, the AERL Link status or the AERL Cloud alert. A restart clears much of this.
• Check the simple things first: breakers and isolators on, cables seated, polarity, supply voltage within range.
• Change one thing at a time, and write down what you changed.
• If the fault is not in this guide, or it comes back after the fix, contact AERL support (Chapter 09).

The full list of warning and fault codes is in Chapter 13, Troubleshooting, of the CoolMax SRX and SRX-R user manuals. AERL Link (aerl.com.au/professionals) shows the active code in plain text.

1.1Status LED

When the SRX is first powered on, it runs a self-test and the LED flashes orange until a charge profile is configured. A red fault code is shown as a number of red flashes (Red Flash Codes, below).

1.2Not Starting or Sleeping

Start-up order: connect the battery first, then turn the PV isolator on. Shut down in reverse: PV isolator off first, wait for the LED to go out, then open the battery breaker. Never open the battery breaker under load.

1.3Orange LED: Setup or Charge Held

1.4Charging Stopped or 0 W

The SRX does not charge until a charge profile is configured for the connected battery. AERL Link's live status shows the charging power (W) and a plain-text status with any active warning or fault.

1.5Earth (Ground) Faults

The SRX checks every connected pole for insulation degradation at start-up and trips a ground fault when the insulation resistance of a monitored pole falls below a fixed 50 kΩ (firmware 2.0.1 and later; earlier firmware offered a Low / Mid / High setting: update the firmware with AERL Link). The chassis must be connected to the same earth as the PV array. Check that 50 kΩ meets your local standards.

On a CAN-controlled system, treat an earth fault as a latched critical alarm: the SRX may keep charging, and its flag can clear before the fault is fixed.

1.6Red Flash Codes

If a fault persists after these actions, contact AERL on 1800 950 865 or [email protected].

1.7CAN Systems: Units Stop With No Code

Most SRX faults clear themselves: the SRX restarts once the condition has cleared, after a hold-off of 10 s to 30 min. If the flags read 0 and the units show output off with no current, work through these checks (SRX CAN Integration Guide, available from AERL on request):

Throttle charging with the current limit, not the voltage target: a voltage target below the battery voltage raises High output voltage (−1154 · −1155).

1.8Firmware Updates

Update over USB with AERL Link. Keep the SRX connected to its battery and powered, and do not disconnect USB, remove power or open the isolators during the update. If an update fails partway, retry: the SRX keeps its previous valid firmware and runs normally until a complete update is received. On the SRX-R, set the MPPT 1 / MPPT 2 selector to the module you are updating, and repeat for the other module.

The Nexus is monitored from AERL Cloud, which shows its online status, last-seen time, firmware version and connection history. It needs no user action in normal operation and applies firmware updates when AERL publishes them.

2.1Status in AERL Cloud

A gateway shows Online (it has reported in the last 15 minutes) or Offline. The equipment on a gateway shows one of four statuses:

2.2Gateway Faults

2.3Devices Missing or Offline

2.4CAN Bus and Termination

The Nexus CAN sockets are linked inside the Nexus (one CAN interface, two sockets), and the Nexus has no built-in termination. A CAN bus needs 120 Ω at each of its two ends and nothing in between:

• Nexus mid-bus (inline, for example battery to CAN 1 and CAN 2 on to the inverter or MPPT): fit no termination plug.
• Nexus at an end of the bus: fit a 120 Ω RJ45 termination plug in the unused CAN socket.

2.5Selectronic SP PRO over RS485

The Nexus has two status LEDs beside its RS485 socket: Tx flickers when the Nexus sends a Modbus request, Rx when the SP PRO replies.

The Nexus must be the only Modbus master on the SP PRO's RS485 port.

3.1Battery LEDs

Below 5% SOC the first SOC LED flashes quickly (1 Hz). While discharging the last lit LED flashes at 0.5 Hz; while charging it flashes slowly, at 0.25 Hz.

3.2Common Faults

Restart in order: shut down the inverter; turn off the DC breaker between battery and inverter; hold ON/OFF on the master battery for 3 seconds; wait until all LEDs are off, then 3 minutes more; turn the DC breaker on; press ON/OFF for 1 second; start the inverter.

3.3Recovering a Flat Battery

If a battery module reaches 0% SOC and its voltage falls below 40 V (over-discharge), recharge it in one of these ways:

1. If the inverter still operates, charge the battery from the inverter.
2. Connect a module at a higher voltage in parallel: it balances and charges the flat module automatically.
3. If inverter charging is not possible, use a 48 V adjustable constant-current charger set to 54 V and no more than 10 A. Charge for at least 30 minutes.

A battery stored for 6 months or more: if its voltage is above 51.6 V it needs no charge (check it every 3 months); below 51.6 V, charge it at 55 V DC and a constant 10 A for at least 30 minutes. If a battery has been submerged in water, stop using it and contact AERL.

3.4Inverter Messages (Managed Mode)

Full settings: LiFe² 5120S Managed Battery Integration Guide.

Kakadu 120 needs an AERL Nexus Gateway to manage the battery communications. Each cabinet holds two independent strings, each with its own BMS and HMI, so the system keeps operating if one string faults.

4.1HMI Indicators

4.2Common Faults

Full procedures: Kakadu 120 Installation and Operating Manual (chapters 5–8) and the Kakadu Commissioning Guide, SP PRO SPLC1202 & CoolMax SRX.

5.1LEDs and Buzzer

EG-600 (two circuits):

All Clear is green and the Circuit Fault LEDs are red. In a fault the buzzer sounds for about 1.5 s, then is silent for 1.5 s, until the fault clears.

EG-600-SC (one circuit):

Both return to All Clear, and close their relays, by themselves once the insulation resistance is back above the trip threshold.

5.2Common Faults

5.3Finding an Earth Fault

1. Prepare. Wear PPE (insulated gloves, safety glasses), follow your isolation procedure and use rated test equipment.
2. Shut down. Turn off the inverter and charge controllers, open the battery breakers and PV array isolators, power down the EarthGuard, and confirm zero voltage with a multimeter.
3. Inspect. Look for damaged cables (including rodent damage) and degraded PV module back sheets.
4. Segment and test. Measure the resistance to earth of the battery conductors, then of the PV array conductors.
5. Repair and restart. Fix the fault and restore power.

5.4Testing the EarthGuard

Caution — potential hazard

An earth fault can damage power conversion equipment (PCE) and connected components. Ask the PCE manufacturer before you simulate an earth fault. AERL takes no responsibility for damage caused by simulating an earth fault.

With the system isolated and the EarthGuard powered down, fit a 10–12 kΩ resistor (20 kΩ maximum; not supplied) between the + or − terminal of the circuit under test and the Earth terminal. Reconnect the battery, restore power and confirm the fault is reported (EG-600-SC: wait 15 seconds): Fault LED, buzzer, relay open. Power down, remove the resistor and reconnect. If nothing trips, check the EarthGuard is powered (one LED lit) and that you can measure the resistor, then repeat. The full procedure is in Chapter 08 of each user manual.

6.1Indicators

The Input Alive LED lights when the input breakers are closed. The Output Alive LED lights when the CoolPro is delivering output. The LCD alternates between the input and output measurements every 5 seconds, each with its voltage, current and the board temperature.

6.2Common Faults

Shut the CoolPro down in this order: turn all three dials fully anti-clockwise, check the LCD shows zero output for 10 seconds (Output Alive turns off), then open the input breakers.

6.3Modbus Communication

Status flags (register 30008): bit 2 input or bit 3 output measurement fault, bit 4 calibration invalid, bit 5 calibration missing, bit 6 temperature sensor fault. Contact AERL if any of these is set; bits 0 (startup) and 1 (daily reset) are normal.

7.1LEDs

At power-on all three LEDs light briefly as a self-test.

7.2Common Faults

The M2HT 25–50 inverter, also used in the All-In-One, shows each fault by name on its display; the All-In-One battery shows codes. Status codes (S01, S02 …) show the inverter's state and are not faults. Full lists: M2HT 25–50 user manual Chapter 08, All-In-One user manual section 7.3.

8.1Inverter Indicators

8.2Common Inverter Faults

An earth fault on the PV array keeps the power indicator red and shows ISO Over Limitation or GFCI Fault until it is cleared; the app and portal show an alarm (email alerts can be set). Install the inverter where the indicator will be noticed.

8.3All-In-One Cabinet and Battery

Cabinet indicators: the audible and visual alarm sounds and flashes when the smoke sensor is triggered; Power (white) is on while grid power is present; Running (green) while the high-voltage box operates; Fault (red) when the cabinet has a fault. Check the alarm details in the monitoring data.

Battery codes starting with E are protection faults (the battery stops to protect itself); I are alarms and W warnings (the system keeps running).

For any fault that persists after these checks, contact AERL support.

9.1Before You Contact AERL

Have ready:

• the product model and serial number, and the firmware version (AERL Link or AERL Cloud);
• what the product shows: LEDs and their pattern, display or AERL Link codes, AERL Cloud alerts;
• for a CoolMax SRX, the AERL Link status and event log; for a Nexus, its serial number and what its LEDs do; for a battery, the number of modules or cabinets and the inverter model and firmware;
• what you have checked and changed, and photos of the installation.

Contact AERL support on 1800 950 865 or [email protected].

9.2Returning a Product

Email the AERL RMA form, with any photos or screenshots, to [email protected] with the serial number as the subject. AERL replies with a Return Materials Authorisation (RMA) number: do not send a product without one. Then send the product, with its RMA number, to AERL, 1/75 Bluestone Circuit, Seventeen Mile Rocks QLD 4073, Australia. For a battery, wait for AERL's shipping instructions before you send it: lithium batteries are dangerous goods. The full process is in the AERL Warranty Claims and Returns Guide.

Warranty terms are in each product's warranty statement, at aerl.com.au. Register a product's warranty at aerl.com.au/warranty-registration.

9.3Change Log