Sandia Aerospace SAFE 128 User Manual

SAFE 128

Avionics Cooling Fan
With Fault Detection

1.1 INTRODUCTION

This sheet describes the installation of the SAFE 128 avionics cooling fan with fault detection output. It is
intended for use by F AA certified repair stations to install the SAFE 128 and includes both mechanical and
electrical installation information. The installer should insure that the SAFE 128 is operating according to its
intended function.

1.1 PRODUCT DESCRIPTION

The SAFE 128 is an avionics cooling fan that provides an operating indication. When the fan is normally
operating, this output is at low impedance. The output goes to high impedance whenever the RPM of the
motor drops below a preset threshold, signaling the connected avionics of the reduction in cooling from the
SAFE 128.

1.2 TECHNICAL CHARACTERISTICS

1.2.1 PHYSICAL CHARACTERISTICS

Width 2.36” Height 2.87”
Depth 1.44” (inc. pins) Weight 0.25 lb

INSTALLATION INSTRUCTIONS

1.2.2 O

PERA TIONAL CHARACTERISTICS

Operating V oltage 22-31Vdc
Current Operating .100 Amps Nominal

Air Flow (No Load) 20 CFM (10CFM @ .08” H2O)
Operating Temp -20 to +55 oC
Max Operating Altitude 55,000 Feet

1.2.3 CERTIFICATION

FAA-PMA PQ0894SW Diamond DA40
DO 160D [F1]BAA[S2R2(B2,M)]XXXXXXZBAZA[XX]M[XXXX][XX]XX

SANDIA aerospace

Albuquerque, New Mexico
www .sandia.aero

Figure 1

Dimensional Drawing

Start-up <.250 Amps

305468-00-IS
Rev B 09/26/06
DRN 287

2.0 INSTALLATION PROCEDURES

2.1 G

ENERAL

The SAFE 128 is supplied with a mounting connector and four contacts. Only three contacts are required and
the spare one is provided in case one is destroyed during installation. The SAFE 128 is also shipped with a
mating connector attached to the unit itself. This is to protect the pins during transit. This connector can be
discarded once the unit is received or may be retained to cover the pin in case return shipment to the factory is
necessary. The SAFE 128 is mounted with four (4) number 6 or 8 screws.

2.2 E

QUIPMENT REQUIRED

2.2.1 Supplied
SAFE 128 System
Includes: SAFE 128 Fan 305468-00

2.2.1 R

EQUIRED BUT NOT SUPPLIED

Four (4) Number 6-32, 8-32 or equivalent mounting screws

2.3 MOUNTING

The SAFE 128 mounts with four number (4) 6-32 or 8-32 or equivalent machine screws. Be sure to observe
the direction of airflow .

Installation Kit 305477-00
Mating Connector 305479-03
Mating Pins 305478

2.4 ELECTRICAL

The SAFE 128 operates on 28Vdc. It will provide a low on Fan Fail (center pin) of the connector when
operating normally. When airflow drops to 60% of nominal, as determined by fan RPM, Fan Fail will output a
high. An external pull-up is required. Power to the SAFE 128 can be supplied from the aircraft buss or from
the unit to be cooled if an ouput is available. If connected to the aircraft buss, the SAFE 128 should be pro­tected by a .5 amp fuse or breaker.

*or equivalent

2.5 C

ALIBRATION

No calibration of the SAFE 128 is required. The unit can be tested by slowing the fan manually and observing
a high present on the Fan Fail pin. Allow the fan to return to normal speed and observe a low on the Fan Fail
pin.

Gnd

Fan

Pwr

Fail

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gnisuoHrotcennoCxeloM59627303-1-2230-974503

tcatnoCpmirCxeloM95724110-05-80874503

looTrepmirCdnaHxeloMANC2622RCro5810-10-11*AN

looTnoitcartxExeloMAN2200-30-11

looTnoiitresnIxeloMAN0000-21836*AN

Mating Connector and Contact Information

*AN

2.6 CONTINUED AIRWORTHINESS

Maintenence of the SAFE 128 is on condition only. No scheduled maintenance is required.

305468-00-IS
Rev B 09/26/06
DRN 287