Sandia Aerospace SAFE 528 User Manual

INSTALLATION MANUAL

SAFE 528

Avionics Cooling Fan
With Fault Detection

1.1 INTRODUCTION

This sheet describes the installation of the SAFE528 Blower with fault detection output. It is intended for use by air­frame manufacturers and certified repair stations to install the SAFE528 and includes both mechanical and electrical
installation information. The installer should insure that the SAFE528 is operating according to its intended function.

1.2 PRODUCT DESCRIPTION

The SAFE528 is an avionics cooling fan that provides an operating indication. When the fan is normally operating, this
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 SAFE528.

1.3 TECHNICAL CHARACTERISTICS

1.3.1 PHYSICAL CHARACTERISTICS

Width 2.10” Height 5.13”
Depth 6.74” Weight 1.19 lb

1.3.2 OPERATIONAL CHARACTERISTICS

Operating Voltage 22-31Vdc
Current Operating .400 AmpsNominal

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

SANDIA aerospace

Albuquerque, NM 87109
www.sandia.aero

Figure 1

Dimensional Drawing

Start-up .550 Amps

305738-00
Rev. B 10/8/12
ECN 3932

1.3.3 CERTIFICATION

FAA-PMA

Beechcraft A36

DO 160D [F1]BAA[S2R2U(F,B2,M)]XXXXXXZBAZA[XX]M[XXXX][XX]XX

2.0 INSTALLATION PROCEDURES

2.1 GENERAL

The SAFE528 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 SAFE528 is mounted with three (3) number 6 or 8
screws. Cooling air is ducted to the device to be cooled using aircraft approved tubing. Unused ports should be capped.

2.2 EQUIPMENT REQUIRED

2.2.1 Supplied

SAFE528 System 705722-00
Includes: SAFE528 Fan 305722-00

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

2.2.2 REQUIRED BUT NOT SUPPLIED

Three (3) or six (6) Number 6-32, 8-32 or equivalent mounting screws depending on mounting.

2.3 MOUNTING

The SAFE528 mounts with three (3) or six (6) 6-32 or 8-32 or equivalent machine screws depending on mounting.

2.4 ELECTRICAL

The SAFE528 operates on 28Vdc. It will provide a low on the Fan Fail pin (center pin) of the connector when operating
normally. When airflow drops to 65% of nominal, as determined by fan RPM, the Fan Fail pin will output a high. An
external pull-up is required. Power to SAFE528 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 SAFE528 should be protected by a 1.0 amp fuse or breaker.

*or equivalent

DO NOT BLOCK AIRFLOW INLET

Gnd

Pwr

Fan
Fail

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Mating Connector and Contact Information

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2.5 CALIBRATION

No calibration of the SAFE528 is required. The unit is tested by slowing the fan manually and observing a high on the
Fan Fail pin . Allow the fan to return to normal speed and observe a low on the Fan Fail pin.

2.6 CONTINUED AIRWORTHINESS

Maintenence of the SAFE528 is on condition only. No scheduled maintenance is required

SANDIA aerospace

Albuquerque, NM 87109
www.sandia.aero

305738-00
Rev. B 10/8/12
ECN 3932