JQX-30F (T91) RELAY (USED)

The JQX-30F, commonly referred to by its industry-standard designation T91, is a high-power miniature relay designed for heavy-duty switching. It is a staple in the power electronics world, particularly for controlling air conditioners, heating elements, and large power inverters.

Key Technical Specifications

The T91 is unique because it is available in two distinct mounting styles depending on your project needs:

1. PCB Mount: All pins are on the bottom, designed to be soldered directly into a high-current circuit board (like your EGS002 Inverter Board).

2. Flange Mount (QC Terminals): The coil pins are on the bottom for the PCB, but the high-current contacts are Quick-Connect (QC) tabs on the top. This is safer for 30A/40A loads because it keeps the heavy wiring away from the delicate control traces on the PCB.

Given the components we have discussed previously, the JQX-30F is the "missing link" for several high-power tasks:

Because it is rated for 30A–40A at 240VAC, this relay can handle the full output of a 2000W–3000W Pure Sine Wave Inverter. It is used to switch the house load from the "Grid" to the "Inverter" during a power outage.

In your EE55 450V Boost Converter, this relay can be placed on the high-voltage DC bus. If the EGS002 board detects an over-current or short-circuit fault, it can trigger the JQX-30F to physically disconnect the 350V–450V supply from the H-bridge.

3. Battery Charger Controller

For the EE55 30A Charger, the T91 is the perfect size to handle the continuous 30A charging current, acting as a "Main Charger Disconnect."

• Coil Kickback: As with the other relays, always use a flyback diode (1N4007) across the coil pins to protect your control IC.