The N321 temperature controller can be used to measure, indicate, and control temperature with a single 16A relay output and adjustable hysteresis — quick to wire and program, offering excellent reliability. The user can program the control action according to the application: direct action (refrigeration) or reverse action (heating). The internal relay can directly switch compressors or electrical heaters with On/Off control, with no SSR required. This 12-24V model suits low voltage applications including vehicles, mobile equipment, and off-grid installations.
The N321 is a trusted product which will replace or upgrade the majority of manual or programmable thermostats used in industry.
✅ 3 Year Manufacturer Warranty — backed by our UK-based technical support
Technical Details
SIZE: 75 x 33 x 75 mm. PANEL CUTOUT: 70 x 29 mm (+0.5 -0.0 mm). SUPPLY: 24V (12~30 Vdc)
INPUT: Thermocouple J/K/T
OUT1: Relay SPDT; 1 HP 250 Vac / 1/3 HP 125 Vac (16 A Resistive)
Thermocouple type J; Range: 0 to 600°C (32 to 999°F); Accuracy: 3°C (5.4°F)
Thermocouple type K; Range: -50 to 999°C (32 to 999°F); Accuracy: 3°C (5.4°F)
Thermocouple type T; Range: -50 to 400°C (32 to 752°F); Accuracy: 3°C (5.4°F)
Frequently Asked Questions
What's the difference between the N321 and N322?
The N321 has a single relay output; the N322 adds a second independent relay output for a second control or alarm function.
Why choose the 12-24V version?
For vehicle applications, mobile equipment, or off-grid installations where mains power isn't available.
Do I need a separate SSR to switch heating/cooling loads?
No — the 16A relay output switches elements, compressors, fans, and valves directly, no SSR required.
Industry Applications
- Mobile & Off-Grid Equipment — low voltage supply for vehicle-mounted or remote installations.
- Refrigeration & Heating Control — programmable direct or reverse action suits both applications.
- HVAC Retrofit — direct upgrade path from bimetallic or capillary thermostats.