Installation Guide and Operating Manual // Model FS20X™ Series 
 
  
 
Honeywell      3 
1.2  Detector Technical Specifications 
1.2.1 Mechanical Specifications 
Enclosure Material:    Copper Free Aluminum (red) 
    316 Stainless Steel 
Physical Dimensions:  Assembly  4.35 in. (
110.49 mm) Height X 4.81 in. (122.24 mm) Diameter 
  Mounting Holes  ¼ in. (
6.35 mm) Diameter, 5.50 in. (139.70 mm) Center to Center 
  Conduit Entries  Two (2) ¾ in. NPT or Two (2) 25 mm 
Weight:  Aluminum  3 lbs. 11 oz. (
1.7 kg) approximately 
  Stainless Steel  7 lbs. 7 oz. (
3.4 kg) approximately 
Enclosure Rating:    IP66 / NEMA 4 / NEMA 4X 
Vibration:    Meets or exceeds Mil Spec 810C, 
    Method 514.2, Curve AW 
1.2.2 Electrical Specifications 
Input Voltage Range:    18 VDC to 32 VDC 
Normal Operation Current:    85 mA (
nominal)  175 mA (nominal with heaterP
1
P
) 
Maximum Fire Alarm Current:    135 mA (
maximum)   220 mA (maximum with heaterP
1
P
) 
Relay Contact Rating:    1 Amp @ 24 VDC resistive 
Analog Current Output:  0.0 to 20.0 mA (
Non-Isolated Source or Sink, User Selectable) 
 (
400 Ohms Max Load [loop resistance])  0.0 mA (<0.6 mA) = Fault 
    2.0 mA (
±0.6 mA) = Dirty Window Lens 
    4.0 mA (
±0.6 mA) = Normal, Safe (no Fault, no Fire)  
    8.0 mA (
±0.6 mA) = Background IR 
    12.0 mA (
±0.6 mA) = Background UV 
    16.0 mA (
±0.6 mA) = Fire Alarm 
    20.0 mA (
±0.6 mA) = Verified Fire Alarm 
Screw Terminal Wire Sizes:    12 AWG to 22 AWG (
2.50 mm to 0.762 mm) 
    Use stranded conductors (
UnotU solid core) 
1.2.3 Environmental Specifications 
Operating Temperature  Standard:  -40° F to +185° F (-40° C to +85° C) 
 
Operating Humidity Range:    0 to 95% RH,  
    100% RH condensing for short periods of time 
Storage Temperature:    -67° F to +221° F (-55° C to +105° C) 
1.2.4 Performance Specifications
P
2
P
 
Field of View:    FS20X detectors have a cone of view of 90° horizontal and 
80° vertical with the highest sensitivity on the central axis 
Sensitivity    One (1) sq. ft. heptane fire at 200 feet (
± 45° from axis) 
Speed of Response:    Typically, 2 to 5 seconds 
High Speed Response:    Less than 0.5 seconds to “fireball” type fires 
Spectral Sensitivity    ~0.185 to 0.26 microns and 0.4 microns to 3.5 microns  
1.2.5  Hazardous Area Classifications (See Section 4.7.3 on Pages 32) 
Class 
I, Division 1, Groups A, B, C & D   
Class 
II, Division 1 Groups E, F & G  Class I, Zone 1, AEx d/ Ex d IIC 
Class 
III  Ex db IIC, Ex tb IIIC 
  T4: Ta = -40°C to +110°C    T4: Ta = -40°C to +110°C 
  T5: Ta = -40°C to +75°C    T5: Ta = -40°C to +75°C 
  T6: Ta = -40°C to +60°C    T6: Ta = -40°C to +60°C 
1 
P
Heater circuit turns ON only when temperature drops below zero degrees Fahrenheit (-17° C)P  
2
 The supply connection wiring shall be rated at least 10°C above the rated service temperature (120°C for T4 applications and 85°C for 
T5 applications)