Data Card; Placard; Power; Electrical Load Analysis - Garmin MX20 Installation Manual

2.5.3 Data Card

The data card is a Compact Flash™ card that contains the database, operating software, and other
information. The data card is required for MX20 operation.

2.5.4 Placard

The aircraft will have a placard identifying the MFD circuit breaker. The placard will be placed directly
adjacent to the respective breaker.

2.5.5 Power

The power and fuse requirements for each external sensor are described in their respective installation
manuals. The MX20 will operate on voltages between 10 and 40 VDC. Install a five amp circuit breaker
for a 14 VDC aircraft and a three amp circuit breaker for a 28 VDC aircraft. Use separate wires for the
heater and CPU power inputs (see Section 3.2); one wire to each pin. Power and ground wires should be
20 AWG. For preservation of essential equipment in aircraft with multiple power busses the MX20
should be powered from the non-essential bus.
Note: Circuits should be protected in accordance with the approved data in this document and the
guidelines in AC 43.13-1B, chapter 11, section 4. Power inputs should be across a minimum of all four
specified input pins.

2.5.6 Electrical Load Analysis

An electrical load analysis should be completed on each aircraft prior to installation in accordance with
AC 43.13-1B, Chapter 11. Use the following values for computation:
Unit
MX20
(1)
MX20 with heater
MX20 I/O
MX20 I/O with heater
Notes:
(1)
Heater element turns on below approximately 30°C. MX20 with pushbutton power/brightness
control does not have a heater.
MX20 Installation Manual
CAUTION
Do not remove the data card with power on.
Table 2-3. Unit Power Loads
(1)
560-1025-09 Rev E
14 VDC
Typical Max
2.0 A 3.0 A
3.0 A 4.0 A
2.5 A 3.5 A
3.5 A 4.5 A
Installation
28 VDC
Typical Max
1 A 1.5 A
1.5 A 2.0 A
1.25 A 1.75 A
1.75 A 2.25 A
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