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on drawing to view large scale version
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| SmartFan
AmpStrip-DC is a modular fan current alarm that monitors
the current drawn by DC fans or blowers and generates failure
signals if it drops below a preset trigger current. AmpStrip-DC
comprises a strip of 6 individual alarm units bused together.
The web separating units can be cut to provide strips to handle
any quantity of fans. Each unit provides alarm signal outputs
for one air mover. The bus distributes power to each unit and
OR’s alarm signals from each unit to provide a single alarm
output if any air mover should fail. Each alarm unit has three
outputs used to drive logic, an LED or a piezo alarm. |
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Features
- 6 alarm unit
strips are easily separated to monitor any quantity of fans
- Separate alarm
outputs are provided for each fan Additionally, alarm signals
from each unit are OR’d
- Permissible
power supply voltage is 11.0 VDC minimum to 25.0 VDC maximum
- Normally open,
normally closed and OR’d outputs provide nominal 11 mA for
an LED and can sink at least 4 mA at 0.4 VDC to drive logic.
Outputs can also drive a piezo alarm. Outputs are referenced
to ground
Normally Closed
(NC) Alarm Output: Closed above trigger current and will
sink 4 mA at 0.4 VDC or less. Open below trigger current and
will accept up to 30 VDC. Referenced to fan negative terminal.
Applies nominal 11 mA to an LED connected from NC to L.
Normally Open
(NO) Alarm Output: Open above trigger current and will
accept up to 30 VDC. Closed below trigger current and will
sink 4 mA at 0.4 VDC or less. Referenced to negative fan terminal.
Applies nominal 11 mA to an LED connected from NO to L. Applies
nominal power supply voltage to a piezo alarm connected from
NO to P.
OR’d (OR) Alarm
Output: OR’d with all other alarm units in AmpStrip. Other
characteristics identical to NO alarm output.
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| SPECIFICATIONS |
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Part
Number
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Maximum
Current to a Fan
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Trigger
Current
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Alarm
Units per Strip
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H109
(1)
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Hardware
Pack
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| Note:
Maximum operating temperature is 65°C ; (1) per alarm unit
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| INSTALLATION |
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| Mounting |
| For
AmpStrip-DC Part numbers 018R6XX to be used as separate alarms,
cut the web separating alarm units at the designed location
with ordinary cutting pliers. |
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| CONNECTIONS
/ JUMPERS |
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Figure
1 Wiring Diagram
Click
on drawing to view large scale version
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| Power-In
Connections (J2) |
| Power
at a voltage between 11 and 25 VDC is applied to J2 at pins
marked - and +. Normally it is necessary to connect power to
only one J2 header in an AmpStrip. However, this connection
is rated at 2.5 Amps maximum. If the total current used by all
fans powered by AmpStrip exceeds 2.5 Amps, power connections
should be made at additional - and + pins. |
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| SUGGESTED
CONNECTING HARDWARE |
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Ref.
Desc.
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Header
on Board (1)
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H109
Hardware Pack
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Quantity
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Description
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Manufacturer
(1)
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Part
Number (1)
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J1
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22-29-2021
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Housing
Terminal (gold)
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J2
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22-29-2071
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Housing
Terminal (gold)
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2
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PCB
Support
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Richco
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CBS-4-19
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| (1)
or equivalent |
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| Fan
Connection (J1) |
| Connect
the DC fan to J1 with polarity as indicated. AmpStrip-DC distributes
input supply power to the fans in addition to sensing their
current. |
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| Fan
Operation Above 25 VDC |
| Though
the maximum voltage that can be applied to AmpStrip-DC is 25
VDC, it can be used with fans operating at higher voltages,
e.g. 48 VDC. In this case it does not distribute power to the
fans. Any supply voltage between 11 and 25 VDC referred to the
negative (reference) voltage used to power the fan may be used.
Connect the negative fan lead to J1:- and connect the positive
fan lead to the + power supply voltage required by the fan.
Connect the low voltage supply (e.g. between 11 and 25 VDC)
to J2:+ and J2:-. Again, the fan’s power supply and the low
voltage supply must have a common negative terminal. |
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| OPERATION
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| Alarm
Outputs (J2) |
| Three
alarm circuits are located on header J2. All circuits are non-isolated,
have the same electrical ratings, and are referenced to board
ground found at J2:- |
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| ALARM
OUTPUT LOGIC |
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Alarm
Output
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Above
Current Trigger
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Below
Current Trigger
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Power
Removed from Unit
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NO
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Short
to Ground
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Open
Circuit
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Open
Circuit
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OR
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Open
Circuit
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Short
to Ground
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Open
Circuit
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CE
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Open
Circuit
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Short
to Ground
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Open
Circuit
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| Power
for an LED alarm indication is provided by Pin J2:L via an internal
12 mADC constant current source. Power for logic gate alarm
circuitry must be provided externally. For logic circuit alarm
indication, each alarm output can sink up to 4 mA at <= 0.4
VDC. When open, a maximum of 30 VDC can be applied to each output.
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| Pin
J2:OR or J2:NO and J2:P and can also be used for a piezo buzzer
alarm output. Below the trigger current, the board supply voltage
(Vs) will be applied to the piezo. Note: L and P are positive
(+); NC, NO and OR are negative (-). |
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