Gardner DELCOS 3100 Controller Field Troubleshooting and Maintenance Guide

Remote start stop: Set [REMOTE Control ON], LED d lights up, controlled through dry contacts on terminals X3.25/X3.26 (closed=remote open, open=remote close).

Pressure switching: The second pressure band can be activated through a timer or external contacts (SR version terminals X4.6/X4.14), and the p2 symbol flashes.

Remote loading/unloading (FS version): External contacts (X3.23/X3.24) are connected in parallel with internal pressure switches for forced loading. Pay attention to the overpressure protection logic (external loading will be temporarily disabled after exceeding the set pressure of 0.5 bar).

7.4 Automatic restart and power outage recovery

Standard automatic restart: only valid when the power outage time is ≤ POWER LOSS TIME (2-999 seconds). There is a START-UP DELAY to stagger before restarting.

Unlimited automatic restart: You need to apply for a code from the Gardner Denver service, and it can automatically restart at any time after a long power outage. Before use, safety regulations must be evaluated, warning signs must be installed, and the computer room must be locked.

Analog output and communication

8.1 Analog output (RS version)

Channel 2: 4-20 mA, corresponding to 0-maximum flow rate. When BLS is activated, the output is the total flow rate of all controlled compressors.

Attention: An isolation amplifier needs to be installed at the output end to prevent interference.

8.2 Analog Output (SR Version, Options)

Channel 1: 4-20 mA, corresponding to 0 to maximum speed.

Channel 2: 4-20 mA, corresponding to 0-maximum flow rate (total flow rate when BLS is activated).

8.3 RS485 Communication

Supports Modbus RTU or DELCOS protocols, baud rates of 4800/9600/19200, and can set station addresses. Combined with Gardner Denver Profibus module or Modbus master, DELCOS 3100 can be connected to higher-level control systems.

Regular maintenance and calibration recommendations

To prevent unexpected shutdowns, it is recommended to perform maintenance according to the following cycles:

Monthly: Clean the ventilation filter of the control cabinet; Check if all wiring terminals are loose; Check the warning records in the fault memory; Observe the status of the water circuit (water level, solenoid valve action).

Quarterly: Calibrate pressure sensors (B1, B2) and temperature sensors (R2); Check the pressure difference of the air filter and replace it if necessary; Check the condition of the motor grease.

Every six months: Backup controller parameters (record all menu settings); Test the emergency stop circuit; Check the discharge time of the SR drive capacitor (measured after power failure).

Every year: replace the real-time clock battery (when Warning BATTERY occurs); Check the solenoid valve and liquid level switch of the water circuit; Verify the safety valve.

Operation after replacing the electronic board:

If the DELCOS 3100 electronic board is replaced, it will require the input of three setup codes after startup. These codes are located on the labels inside the electrical control cabinet. After input, all parameters will be restored to their factory default values. It is necessary to reconfigure: optional input allocation, BLS parameters, water circuit parameters, pressure set points, communication parameters, etc.

Fault case sharing

Case 1: The RS version compressor frequently reports "FAULT CONVERTER", but the frequency converter panel has no faults

Phenomenon: Sudden shutdown during operation, displaying FAULT CONVERTER. Check that the frequency converter has no alarms, and the multimeter measures that there is no 24V signal at the "ready" output terminal of the frequency converter.

Reason: The auxiliary contacts of the frequency converter are aging and have poor contact. Sometimes there is no measurement.

Solution: Replace the auxiliary relay of the frequency converter; Simultaneously check the 24V power supply and wiring terminals inside the frequency converter.

Case 2: SR version displays "FAULT SR-DRIVE (52)" and "FAULT SR-LOCKOUT (3)"

Phenomenon: Immediately display CAN communication error after power on, unable to start.

Troubleshooting: Check if the flat cable connection between the measurement control board and the gate drive board is secure; Check the CAN bus terminal resistance (120 Ω). The plug J19 (emergency stop connection) was found to be loose, and the fault disappeared after re plugging it.

Case 3: Frequent occurrence of Warning Supply 2 in the water circuit

Phenomenon: Water replenishment exceeds the time limit, and the actual pressure tank water level remains low.

Inspection: The inlet solenoid valve is not functioning. The resistance of the multimeter coil is infinite, and it is normal after replacing the solenoid valve. At the same time, check if the water supply pump of the water treatment unit has sufficient pressure.