Description
The Honeywell T921A1191 is a proportional low-voltage thermostat designed for precise temperature control in heating and cooling systems that utilize valve motors, damper motors, and balancing relays.
Technical Specifications
| Condition |
New/Never Used Surplus |
| Brand |
Honeywell |
| Category |
Controls & Indicators |
| Subcategory |
Thermostat |
| Part Number |
T921A1191 |
| Product Type |
Proportional Low Voltage Thermostat |
| Type |
Low Voltage Thermostat |
| Application |
Valve Motors, Damper Motors, Balancing Relays (Heating/Cooling Systems) |
| Voltage |
24–30 VDC |
| Control Output |
135-ohm Potentiometer |
| Scale |
Fahrenheit |
| Temperature Range |
56°F to 84°F (13°C to 28°C) |
| Mounting |
Wall mount (Horizontal orientation) |
| Dimensions |
5.68 × 3.37 × 2.25 in (144 × 86 × 58 mm) |
| Housing Color |
Gray |
| Housing Material |
Thermoplastic |
| Control Type |
Proportional (Manual Dial) |
| Ambient Temperature Limits |
32°F to 122°F (0°C to 50°C) |
| Electrical Connections |
Terminal block or pigtail leads (depending on model) |
| Application Environment |
Commercial/Industrial |
| Indicator Type |
Analog scale (Fahrenheit) |
| Enclosure Rating |
Indoor use only |
| Power Requirement |
None (self-powered via control circuit) |
| Weight |
0.90 lb (0.41 kg) |
Information About T921A1191
The Honeywell T921A1191 is part of the T900 series of low-voltage proportional thermostats known for their high accuracy and compatibility with pneumatic and electric actuator control systems. It features a 135-ohm potentiometer element, translating temperature changes into proportional voltage or current signals for precise modulation of valve and damper motors. With a sleek gray housing and horizontal wall-mount design, the thermostat is ideal for installations in offices, hospitals, schools, and other commercial spaces requiring reliable, long-term environmental control.
Key Features:
- Proportional Control Thermostat: Provides smooth, linear output signals for modulating devices, enabling stable room temperature without cycling.
- Low Voltage Operation: Designed for systems operating at 24–30 VDC—ideal for electric valve and damper motor applications.
- Wide Temperature Range: Adjustable setpoint from 56°F to 84°F (13°C to 28°C) for broad environmental compatibility.
- Precision Potentiometer Element: Equipped with a 135-ohm potentiometer for accurate proportional output signal response.
- Universal Compatibility: Works with valve motors, damper motors, and balancing relays in both heating and cooling configurations.
- Durable Housing: Constructed with a gray thermoplastic case, offering long service life in commercial settings.
- Horizontal Wall Mounting: Simple installation and aesthetic integration with standard electrical wall boxes.
- Smooth Manual Adjustment: Easy-to-use temperature dial with Fahrenheit markings for intuitive setpoint control.
- Stable and Reliable Operation: Mechanical components engineered for minimal wear and extended calibration stability.
- Compact Design: Low-profile housing suitable for both retrofit and new installations in modern HVAC systems.
The T921A1191 offers dependable, energy-efficient proportional temperature regulation for precise indoor climate control in professional and industrial environments.
