Table 8: A421 Series Electronic Temperature Controls
Input signal 1,035 ohm at 77°F (25°C) for A99 PTC Temperature Sensors
Accuracy Combined accuracy of A421 Control and A99 sensor: ±2°F (±1°C) between
5°F and 167°F (-15°C and 75°C); diverging to ±3°F (±2°C) at -40°F (-40°C) and
±3°F (±2°C) at 212°F (100°C)
Sensor offset range ±5ºF or ±3ºC
Enclosure material Type 1, IP20 high-impact thermoplastic or
Type 4X, IP66 watertight, corrosion-resistant, high-impact thermoplastic
Compliance North America: cULus Listed; UL 60730, File E27734, Vol. 1; FCC Compliant
to CFR47, Part 15, Subpart B, Class B
Industry Canada (IC) Compliant to Canadian ICES-003, Class B limits
Europe: CE Mark – Johnson Controls declares that this product is in
compliance with the essential requirements and other relevant provisions
of the EMC Directive; Low Voltage Directive.
Australia and New Zealand: RCM, Australia/NZ Emissions Compliant
Table 9: A421 Temperature Control Output Relay Contacts electrical ratings
Agency and file UL 60730 and EN 60730
Applied AC voltage at 50/60 Hz 120 VAC 208 VAC 240 VAC
Horsepower LC/LNO (LC/LNC) 1 (0.25) 1 (0.3) 1 (0.5)
Full load amperes LC/LNO (LC/
LNC)
16 (5.8) 9.2 (4) 8 (4.9)
Locked rotor amperes LC/LNO (LC/
LNC)
96 (34.8) 55.2 (24) 48 (29.4)
Resistive amperes LC/LNO (LC/
LNC)
15 (10) 10 (10) 10 (10)
Pilot duty VA LC/LNO (LC/LNC) 125 (125) 125 (125) 125 (125)
Table 10: UL conformity declaration information
Information Description
Purpose of control Sensing control / operating control
Construction of control Electronic independently mounted control
Number of cycles 30,000 cycles
Method of mounting control Mounting screws or DIN rail
Type 1 or type 2 action Type 1.B (Micro-disconnection)
External pollution situation All models: A421 [ ] B: Pollution degree 3
All models: A421 [ ] E: Pollution degree 4
Internal pollution situation Pollution degree 2
Heat and fire resistance category D
Rated impulse voltage 4,000 V
Ball pressure temperature 128°C
Cover screw torque requirements
instruction
All models: A421 [ ] E: To maintain type 4X / IP66 rating,
tighten enclosure screws to 10–12 in·lb
A421 Series Electronic Temperature Controls with Off-Cycle Defrost Installation Guide26