Solid-State Starters Ð Troubleshooting guides and in- formation pertaining to the operation of the solid-state starter may be found in Fig. 44-46 and Table 11.

Attempt to solve the problem by using the following preliminary checks before consulting the troubleshooting table.

When the power is off:

·Inspect for physical damage and signs of arcing, overheat- ing, etc.

·Is the wiring to the starter correct?

·Are all connections in the starter tight?

·Is the current feedback resistor properly adjusted and installed?

·Is a heater coil installed in each leg of the motor?

·Is the control transformer fuse blown?

·Is the motor connected to the starter?

TESTING SILICON CONTROL RECTIFIERS IN BENSHAW, INC. SOLID-STATE STARTERS Ð If a sili- con control recti®er (SCR) is suspected of being defective, use the following procedure as part of a general trouble- shooting guide.

IMPORTANT: Before performing the SCR check be- low, remove power from the starter and disconnect the motor terminals T1, T2, and T3.

1.Connect ohmmeter across terminals L1 and T1. Resis- tance reading should be greater than 50,000 ohms.

2.If reading is less than 50,000 ohms, remove connecting bus heatsink between SCR3 and SCR6 and check anode to cathode of SCR3 and SCR6 separately to determine which device is defective. See Fig. 44. Replace defective device and retest controller.

3.Repeat Steps 1 and 2 across terminals L2 and T2 for SCRs 2 and 5.

4.Repeat Steps 1 and 2 across terminals L3 and T3 for SCRs 1 and 4.

If the SCRs tested were not defective but the problem still persists, refer to the following Steps 5 and 6.

5.Disconnect the SCR1 from the white gate and red cath- ode wires on the AK control logic card. With an ohm- meter set on Rx1, check between white and red wires.

LEGEND

SCR Ð Silicon Control Recti®er

Fig. 44 Ð Typical Benshaw, Inc. Solid-State

Starter (internal View)

Resistance should normally be between 8 and 20 ohms average. Excessively high or low resistance may be indicative of a defective logic card. Replace and retest.

6.Repeat Step 5 for SCR leads 2 through 6. Care should be taken to ensure that the gate and cathode wires are replaced exactly as they were: white wire to gate (G1 through G6); red wire to cathode (K1 through K6).

Damage to the starter may result if wires are reversed.

If the problem is still not resolved, consult the starter manu- facturer for servicing.

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Carrier 19XL specifications Typical Benshaw, Inc. Solid-State Starter internal View
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19XL specifications

The Carrier 19XL is a highly regarded commercial heating and cooling solution, designed to provide optimum performance and energy efficiency in various applications. This rooftop unit is engineered to meet the diverse needs of businesses, making it an ideal choice for those requiring reliable climate control in their facilities.

One of the standout features of the Carrier 19XL is its advanced cooling and heating capabilities. The unit utilizes a high-efficiency scroll compressor that ensures a quieter operation and improved reliability. The system can operate across a wide range of temperatures, making it versatile for various climates. Additionally, it offers both cooling and heating options, allowing for year-round comfort.

Energy efficiency is a focal point of the 19XL design. With an impressive Seasonal Energy Efficiency Ratio (SEER) and Heating Seasonal Performance Factor (HSPF), this unit not only helps reduce energy costs but also supports environmental sustainability initiatives. The unit is equipped with environmentally friendly refrigerants, further contributing to lower greenhouse gas emissions.

The Carrier 19XL features a user-friendly control system, allowing for easy monitoring and management of the unit's performance. This control system is designed to maximize energy savings, offering features such as demand control ventilation and integrated economizers that facilitate the use of outdoor air for cooling, reducing reliance on mechanical systems when conditions allow.

Construction-wise, the Carrier 19XL is built to withstand tough environmental conditions. Its robust cabinet is made from galvanized steel, providing durability and protection against the elements. The design also includes insulation to minimize noise levels, creating a more comfortable indoor environment.

Maintenance is a key consideration in the design of the 19XL. The unit features accessible service ports and a simplified access panel, allowing technicians to perform routine maintenance with ease. This proactive design helps ensure the longevity of the system and minimizes downtime, keeping operations running smoothly.

In summary, the Carrier 19XL is an exceptional choice for commercial heating and cooling needs. With its energy-efficient features, advanced technology, and durable construction, it stands out as a reliable solution for businesses looking for sustainable climate control options.
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