Installation – SmartFan TachScan-3 Fan Speed Alarm

Fan Connections
For three wire DC fans operating at supply voltages between 6.0 and 60.0 VDC, TachScan-3 distributes power to the fans in addition to accepting tachometer pulses from the fans. Connect the fan wires to J1, J2 and J3 using the suggested hardware, or equivalent. For applications using less than three fans, any of the three connectors (J1, J2, J3) can be used to monitor tachometer signals. The fan wires are usually color coded with red for +, black for – and white or yellow for A (alarm). Input current must not exceed 4.0 Amps. When TachScan-3 is used with a SmartFan speed controller, the power output of the speed controller is connected to J7.

AC Fan Alarm Monitoring
Order these part numbers when using TachScan-3 with AC fans.
P/N 030M3205-F for 1 mA Alarm Sinking Current
P/N 030M320R4-F for 100 mA Alarm Sinking Current
TachScan-3 cannot distribute AC power to AC fans. AC fans usually have 5 wires, 2 for power and 3 for the tachometer pulse circuit. Connect the AC fan power leads to the rated source of power. Connect the tachometer pulse leads (+, -, tach pulse) to J1, J2, and J3. TachScan- 3 distributes power to run the tachometer pulse circuits within the fans. Apply a DC voltage as specified by the fan manufacturer for the tachometer pulse circuits at J7.

Use with a SmartFan Speed Controller
Because of the wide range of power supply voltages that may be connected to J7, TachScan-3 may be used with any DC SmartFan speed controller. The power output of the speed controller that would otherwise be connected directly to the fan load is instead connected to J7. TachScan-3 in turn distributes this power to the fans.

Figure 1: Typical wiring diagram
J1 – Fan Power and Tach Input
J2 – Fan Power and Tach Input
J3 – Fan Power and Tach Input
J4 – Alarm channels Setting
J5 – Trigger Speed Setting
J6 – Alarm Outputs
J7 – Supply Power P/Ns 030M320-F and 030M3205-F
R2 >= V2/1, kOhms
R1 >= V1/1, kOhms
P/Ns 030M320R-F and 030M320R4-F
R2 >= V2/100, kOhms
R1 >= V1/100, kOhms
Above Trigger Speed
Sense_VA = V1 VDC
Sense_VB = <0.4 VDC
Below Trigger Speed
Sense_VA = <0.4 VDC
Sense_VB = V2 VDC
Figure 2: Multi-board configuration for variable fan speed control and tachometer alarm monitoring.

Suggested Connecting Hardware – SmartFan TachScan-3 Fan Speed Alarm

TachScan-3 Connectors H115-F Hardware Pack
Ref. Desc. Header on Board1 Quantity Description Manufacturer1 Part Number1
J1, J2, J3 22-29-2031 3
Terminal (Gold)
Molex 22-01-3037
J6, J8 22-29-2041 2
Terminal (Gold)
Molex 22-01-3047
J7 22-29-2021 1
Terminal (Gold)
Molex 22-01-2027
4 PCB Support Richco CBS-4-19

1or equivalent

ADDITIONAL MANUAL PAGESOperation/Installation Manual

Use the links below for addtional manual pages or for a complete manual or click on the Operation/Installation Manual PDF link above.

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