COMPACT VAV CONTROLLER WEB-VA423B24N – INSTALLATION INSTRUCTIONS 
 
   
  19      31-00362-01 
 
RELATED TECHNICAL LITERATURE 
Table 9. Related Technical Literature 
Product 
Literature 
Number 
Spyder Model 5 WEB- Compact 
VAV controller VA423B24N - 
Mounting instructions 
Spyder Model 5 WEB- Compact 
VAV controller VA423B24N – 
Product data 
Spyder Model 5 – Engineering Tool 
User Guide 
TR40x/TR42x – Specification Data 
TR40x/TR42x – Installation 
Instructions 
TR40x/TR42x – Operating Guide 
TR2x Series – Specification Data 
TR2x Series – Installation 
Instructions 
TR120 – Specification Data 
TR120 – Installation Instructions 
TR75 – Specification Data 
TR75 – Installation Instructions 
C7400S – Specification Data 
C7400S – Installation Instructions 
 
APPENDIX  
Sensor Input Accuracy 
The controller's internal sensor inputs support NTC20 kΩ 
sensors. The following table lists the typical minimum 
accuracies of the hardware and software for these 
temperature sensors. 
 
Table 10. Accuracies of internal NTC20kΩ sensor 
inputs of the controller 
Measurement 
error (excluding 
sensor 
characteristics) 
-58 to -4 °F (-50 to -20 °C) 
-4 to +32 °F (-20 to 0 °C) 
86 to 158 °F (30 to 70 °C) 
158 to 212 °F (70 to 100 °C) 
212 to 266 °F (100 to 130 °C) 
266 to 302 °F (130 to 150 °C) 
302 to 752 °F (150 to 400 °C) 
•  This is the accuracy of the internal 
sensor input (hardware + software 
[linearization]), only. This table does not 
include the characteristics of the 
sensors, themselves (see section “Sensor 
Characteristics below). If a different 
sensor or sensor accuracy is required, 
one may instead use the inputs of, such 
as a connected Panel I/O module. 
Recognition of Sensor Failure of Sensor 
Inputs 
The thresholds at which sensor failures – i.e., 
sensor breaks (SB) and short-circuits (SC) – are 
recognized depends upon the given sensor type. In 
the event of a recognized sensor failure, the sensor 
assume the safety values configured in CARE. 
Table 11 lists the measurement ranges and the 
corresponding thresholds for the recognition of 
sensor failure for the various different sensor types: 
 
Table 11. Thresholds for short-circuit (SC) and 
sensor-break (SB) recognition 
2to10 V / 4to20 mA 
(without pull-up) 
SC: < 1.5 V / 3 mA; 
SB: no recognition 
-58 to +302 °F  
(-50 to +150 °C) 
SC: < 20 Ω; SB: < -
94 °F (-70 °C) 
-22 to +752 °F  
(-30 to + 400 °C) 
SC: < 775 Ω; SB: < -
58 °F (-50 °C) 
In the case of temperatures lying outside the 
aforementioned ranges, the lowest/highest value 
within the range, instead, will be communicated. 
Thus, a temperature of -51 °F will be 
communicated as “-50 °F.” 
Sensor Characteristics 
The characteristics (resistance in relation to 
temperature) of the sensors and the resultant 
voltage are listed on the following pages. The 
stated values do not include failures due to sensor 
failures; wiring resistance or wiring failures; 
misreading’s due to a meter connected to measure 
resistance or voltage at the input.