SZ-7524 Series | Freezer Temperature Controller with 3 Relays & Dual NTC Probes

Product Summary

The Sub-Zero SZ-7524 Series is a compact and robust temperature controller designed for freezer and cold room applications. It comes with 3 relay outputs (Compressor, Fan, Defrost – 8A each) and 2 NTC probe inputs for accurate temperature and evaporator coil monitoring.
Available in two variants:

• SZ-7524P – Advanced model with IP65 front protection, EEPROM memory, and enhanced defrost algorithms.

• SZ-7524T – General-purpose freezer controller with compressor & door fault input, touch keypad, and temperature logs.

Both models are built for reliable refrigeration control, efficient compressor protection, and consistent temperature management.

Key Features

• 3 Relay Outputs: Compressor (8A), Fan (8A), Defrost (8A)

• Input: 2 × NTC probes (Room & Evaporator coil)

• Advanced defrost control: Time & temperature-based, auto/manual options

• Settable ON/OFF delay for compressor protection

• Password protection for secure parameter settings

• Touch-sensitive keypad for easy operation

• EEPROM data memory (SZ-7524P) for long-term reliability

• IP65 front protection (SZ-7524P) for tough environments

• High & Low temperature alarms/logs (SZ-7524T)

• Compact panel-mount design with 71 × 29mm cutout

Applications

• Freezers & refrigerated tables

• Small cold rooms

• Cold storage monitoring

• Chillers & refrigeration cabinets

• Industrial & commercial refrigeration systems

Product Benefits

• Dual probe monitoring ensures accurate room & coil temperature control

• Enhanced defrosting for efficient cooling performance

• Built-in compressor safety with ON/OFF delay algorithms

• Reliable operation in harsh refrigeration environments

• Compact design for easy panel mounting

• Long-term stability with EEPROM data retention (SZ-7524P)

• User-friendly setup with password protection and keypad lock

FAQ

Q1: What is the difference between SZ-7524P and SZ-7524T?
A1: The P model includes IP65 frontal protection, EEPROM memory, and advanced defrost algorithms. The T model offers digital inputs for compressor/door faults and temperature logging features.

Q2: How many relays are available in this controller?
A2: Both variants include 3 relays: Compressor, Fan, and Defrost (8A each).

Q3: What probes are supported?
A3: Both models support dual NTC probes for room and coil temperature sensing.

Q4: Can it be used for cold rooms as well as freezers?
A4: Yes, the wide temperature range (-50°C to +50°C) makes it suitable for freezers, cold rooms, and other refrigeration applications.

Q5: How is the controller mounted?
A5: It is designed for flush panel mounting with a standard 71 × 29 mm cutout.