Wisp II —
INSTALLATION
Mounting
Installation & Operation
+
RED
Vs
Supply
Voltage
WHITE
Mount Wisp II in a moving air stream using the
cable clamp supplied. Avoid placing the sensor
(located at the tip) near a hot component as this
may result in heating by radiation. To minimize
heating of the sensor by the Wisp II circuits,
avoid mounting the unit vertically with the
sensor at the top.
-
BLACK
Figure 3
Connection diagram for P/N 048W0XX and P/N 018W1XX when
the temperature alarm output is not used.
Location
Install a closed-loop unit at or near the equip-
ment exhaust where it can sense any upstream
event that could affect cabinet temperature.
Install an open-loop (P suffix) unit at or near
the equipment inlet.
OPERATION
Fan Speed vs. Sensor Temperature
The relationship between fan speed, as a per-
centage of full speed, and sensed temperature
is shown in Figure 4. Full speed occurs at the
Control Temperature (T
c
). Minimum speed tem-
perature (approx. 50% of full speed) depends
on part number. For closed loop units, the “X”
in Figure 4 is equal to 4. For open loop units the
“X” in Figure 4 is equal to 12.
Fan Speed vs. Sensor Temperature
100%
Connections
+
Vs
Supply
Voltage
R1
LED
RED
-
WHITE
YELLOW
BLACK
Figure 1
Connection diagram for P/N 018W0XX with
LED temperature alarm indication.
Resistor (R1) = (Vs -2)/ 10, kOhms
Figure 4
Fan speed vs
sensor temperature
50%
+
Vs
Supply
Votlage
R2
V1
Logic
Voltage
TC - XºC
TC ºC
VA
RED
-
WHITE
YELLOW
BLACK
Voltage Regulator and Limiter
Part Nos. 048W0XXX are intended to cover
telecommunications applications using supply
voltages ranging from 38 to 75 VDC. Wisp II
regulates minimum (idle) voltage at 26 VDC.
Maximum voltage applied to the fans is limited
to 50 VDC. For supply voltages above 50 VDC,
power is linearly derated based on the curve
shown in Figure 5.
Power Rating vs. Supply Voltage
R2 >= V1 / 4, kOhms Above Trigger: Va <= 0.4VDC
Below Trigger: Va = V1
Figure 2
Connection diagram for P/N 018W0XX with
logic circuit temperature alarm indication.
Temperature Alarm Output
For Part Nos. 018W1XXX, a temperature alarm
signal is available through the yellow and black
wires. An alarm can be indicated using an
external LED (Figure 1) or logic circuit (Figure 2).
Alarm Type:
Trigger:
Alarm States:
Max. Voltage:
Max. Current
Non-Isolated Open-Collector
10°C Above Control Temperature
Conducting (Closed), Above Trigger
Cut-Off (Open), Below Trigger
30 VDC
4 mA DC at 0.4 VDC (Logic Circuit),
10 mA DC (LED Circuit)
20 W
Figure 5
Power derating curve
10 W
40
50
60
VDC
70
CONTROL
RESOURCES
INCORPORATED
E-mail: sales@controlres.com
s
Web: www.controlres.com
29
ETC [ ETC ]
