-53-
BELFORT
INSTRUMENT
Proprietary Information
10.6 P
OWER
S
UPPLY
R
EPLACEMENT
I
NSTRUCTIONS
SAFETY PRECAUTIONS
1. Do not perform outdoor Belfort AWOS maintenance tasks during a thunderstorm.
2. Use extreme caution when lowering the tilt-over tower whenever ice or snow has accumulated
on the tower cross arm or the sensors. The extra weight may cause the tower to fall over
rapidly.
TOOLS & PARTS REQUIRED
Small slotted screw driver
Removal Procedur
es:
Refer to figure 13.
1.
At the DATU display terminal, issue a NOTAM advisory to alert users that the Belfort AWOS
system is being serviced prior to beginning investigation of this fault. The NOTAM to be
issued is "
Belfort AWOS system being serviced, do not use current weather data
outputs
." Verify that this NOTAM advisory is displayed on the operator screen prior to
beginning this maintenance tasks. Refer to the "Belfort AWOS Operator Manual" for
instructions on how to enter and delete NOTAMs.
2.
Power down the power enclosure by opening the AC and DC circuit breakers.
3.
Use a DMM set to AC volts, and measure the voltage on the AC input terminals of the power
supply. The voltage read should be <1.0 vac.
4.
In the power enclosure, locate the +12v dc or the +14v dc power supply to be replaced.
5.
With the screw driver, loosen the screws to release the AC feed wires, L one black, N white
and green.
6.
With the screw driver, loosen the screws to release the DC output wires:
+12v supply +V red wire, -V black wire;
+14v supply +V red wire, +V white wire, -V black wire, -V green wire;
7.
With the screw driver release the power supply catch mechanism that secures the supply to
the din rail.
8.
Examine the replacement power supply. If the replacement supply is the same model supply,
then mount the supply onto the din rail in the same orientation as the original.
9.
With the screw driver, insert the wires and tighten the screws to secure the AC feed wires, L
one black, N white and GND green.
10.
With the screw driver, insert the wires and tighten the screws to secure the DC output wires:
+12v supply +V red wire, -V black wire;
+14v supply +V red wire, +V white wire, -V black wire, -V green wire;
11.
Check and confirm that the wires are connected as indicated above.
12.
With the DMM set to resistance, measure across the AC wires and the DC wires. Confirm
that there are no shorted wires. If any shorts exist, use the DMM to locate and resolve.
13.
Power up the power enclosure by enabling the AC circuit breaker only.
14.
With the DMM set to AC volts, measure across the AC input terminals L and N. Confirm
that the AC voltage >110vac is present. If no Ac voltage, turn off the AC supply at the breaker
and race the wire connections against the power enclosure wiring diagram. Fix any wiring
errors.
Summary of Contents for AWOS
Page 17: ... 14 BELFORT INSTRUMENT Proprietary Information Figure 2a Securing the Tower for Maintenance ...
Page 49: ... 46 BELFORT INSTRUMENT Proprietary Information Figure 9 Temperature Humidity Sensor Removal ...
Page 51: ... 48 BELFORT INSTRUMENT Proprietary Information Figure 10 Visibility Sensor Removal ...
Page 60: ...BELFORT INSTRUMENT Proprietary Information Appendix A Belfort AWOS Maintenance Forms ...
Page 66: ...BELFORT INSTRUMENT Proprietary Information This page intentionally left blank ...
Page 74: ...BELFORT INSTRUMENT Proprietary Information Appendix C UHF Transceiver Specifications ...
Page 88: ...BELFORT INSTRUMENT Proprietary Information Appendix F DCP Site Configuration Procedure ...
