Product Description
Toyota OEM part number 00591-30738-81 is a 300A 36/48V power contactor designed for electric lift truck applications. Featuring normally open contacts, silver alloy construction, and compatibility with 36VDC and 48VDC battery systems, this contactor is engineered to handle high inrush and continuous currents in industrial vehicle drive circuits.
Specifications
Electrical
| Rated Voltage | 36VDC and 48VDC |
| Continuous Current Rating | 300A |
| Device Type | Power Contactor, Single-Pole Normally Open (NO) |
| Pick-Up Voltage | ≥80% of rated coil voltage |
| Drop-Out Voltage | ≤30% of rated coil voltage |
| Max Switching Frequency | 600 cycles/hour |
Part Numbers
| OEM Part Number | 00591-30738-81 |
| Manufacturer Part Number | TO 00591-30738-81 |
Frequently Asked Questions
Q: What makes the TO 00591-30738-81 different from the 15A and 150A contactors?
A: The TO 00591-30738-81 is a high-capacity 300-ampere power contactor designed for battery-to-motor drive circuits in electric lift trucks. Unlike the 15A and 150A control contactors that manage signal switching, this unit handles the main power circuit, controlling high inrush and continuous currents in the motor drive system. It supports both 36VDC and 48VDC battery systems.
Q: What voltage systems is this contactor compatible with?
A: The TO 00591-30738-81 is rated for both 36VDC and 48VDC battery systems. The 36V configuration is common in lighter-duty electric pallet jacks and walkie stackers. The 48V configuration is used in larger sit-down rider trucks and heavy-duty reach trucks. The contactor is a single-pole normally open device, meaning it connects or disconnects the main battery voltage to the motor controller.
Q: What is the difference between pick-up voltage and drop-out voltage?
A: Pick-up voltage is the minimum coil voltage at which the contactor will close its contacts, approximately 80 percent of rated voltage. Drop-out voltage is the maximum coil voltage at which the contactor will release its contacts, approximately 30 percent of rated voltage. This hysteresis prevents unwanted chattering if coil voltage fluctuates during truck operation.
Q: Why is silver alloy construction important for a 300A power contactor?
A: At 300 amperes, the TO 00591-30738-81 generates significant heat and arcing stress during switching. Silver alloy contacts resist pitting, arcing erosion, and oxidation far better than bare copper. Silver provides excellent thermal and electrical conductivity, dissipating heat efficiently and maintaining low contact resistance across the service life of the device.
Q: Can this contactor handle motor inrush current?
A: Yes. The TO 00591-30738-81 is engineered to handle both high inrush currents during motor startup and continuous operating current. When the lift truck motor is first energized, inrush current can spike well above the 300-ampere continuous rating for a brief moment. The contactor is rated to withstand these transient peaks without damage.
Q: Which lift truck models and battery voltages use this part?
A: The TO 00591-30738-81 is used in Toyota electric lift trucks equipped with 36VDC or 48VDC battery systems that require main power contactor control. This includes sit-down rider trucks, heavy-duty reach trucks, and large-capacity pallet jacks. Verify your truck battery voltage and control system specifications, as selecting the correct voltage-rated contactor is critical for safe operation.