CLARK FZ5024A 36/48V PUMP AC2 INVERTER CONTROL 8051761 #1 17:19

The CLARK FZ5024A (ZAPI PUMP AC2) is a programmable, single-function DC motor controller designed exclusively to operate the hydraulic pump motor on an electric forklift or other material handling equipment.

Its sole purpose is to power the pump that creates hydraulic pressure for lifting and lowering loads, tilting the mast, and operating any attachments. It receives signals from the operator’s hydraulic controls (levers/buttons) and delivers the precise amount of power to the pump motor to perform the requested function at the desired speed.

Key Specifications from the Label

• OEM Brand: CLARK

• Clark Controller Model: FZ5024A

• Clark Part Number: 8051761

• Actual Manufacturer/Technology: ZAPI (The “AC2” is a ZAPI series identifier for pump controls).

• Function: PUMP INVERTER CONTROL (Dedicated hydraulic pump controller).

• Operating Voltage: 36V or 48V DC (Compatible with both battery systems; must be configured for the correct voltage).

• Current Rating: The “#1” is a Clark-specific amperage code. For pump controllers, #1 typically indicates a lower amperage rating, often in the range of 90-110 Amps. This is sufficient for most standard hydraulic pumps.

Key Features and Functions

• Dedicated Pump Control: Designed specifically for the demanding start-stop and variable speed needs of a hydraulic pump motor. It is not designed to control traction.

• Smooth & Precise Control: Provides smooth acceleration of the hydraulic pump, reducing mechanical shock to the system and allowing for precise load handling (e.g., fractional lifting/lowering).

• Programmability: Requires a specialized programmer (typically a ZAPI unit) to configure parameters such as:

  • Maximum pump speed (for lift and lower)

  • Acceleration and deceleration (ramp) rates

  • Current (torque) limit to protect the pump motor and hydraulic system from overload

  • Diagnostic settings

• Integrated Diagnostics: Features self-diagnostics and can store error codes for faults like:

  • Pump motor over-current

  • Controller over-temperature

  • Short circuit

  • Low battery voltage

• Protection Circuits: Built-in protection for the pump motor and itself, including thermal overload and under-voltage shutdown.

Common Applications

This controller is found on 36V/48V Clark electric material handling equipment where the pump is controlled separately from the drive. Examples include:

• Clark Electric Forklifts (where a separate ZAPI DUALAC2 handles traction)

• Clark Electric Reach Trucks

• Clark Electric Pallet Trucks

Important Notes for Replacement/Repair

1. Function is Critical: This is only a pump controller. It cannot be used to replace a traction controller (like a DUALAC2) or a combined controller (like a COMBIAC2).

2. ZAPI Technology: While the label doesn’t say “ZAPI” explicitly, the “AC2” nomenclature is proprietary to ZAPI. It should be treated as a ZAPI component for programming and diagnostic purposes.

3. Amperage Match: The amperage code (#1) must be matched when replacing. Using a pump controller with a different rating (e.g., a higher amperage #2) could lead to improper operation or damage to the hydraulic system.

4. Programming is Required: A new or replacement unit will need to be programmed with the correct parameters for the specific vehicle.

5. Core Value: This unit has a core value and should be returned for a credit if exchanging for a rebuilt one.