Electronics International VA-1A User Manual

Page 10

VVA-1A

A-1A

A-1A, V

, V

, VA-1A-

A-1A-

A-1A-XX

Installation Instructions

II 040934

Rev: C 2/24/92

General Information

There are two types of volt/amp meters used in aircraft: Internal Shunt Units and External Shunt Units.

1. Internal Shunt Units:

Electronics International Inc. manufactures a VA-1A which is our only internal shunt unit. It has the shunt
built into the unit, has two large lugs on the back of the unit and all of the electrical current passes through
this gauge. Use this gauge if your aircraft is currently wired for an internal shunt unit or if you elect to route
your main alternator or battery supply line up to the instrument panel. As with all internal shunt units, the
current capability is limited. The VA-1A is capable of handling 100 amps continuous current. If your
aircraft’s electrical system is designed to draw more than 100 amps continuous current, you should use one
of our external shunt units.

2. External Shunt Units:

An external shunt is a strip of metal, usually mounted on a bakelite base. This metal is made of special alloys
to produce a very small, precise signal when current passes through it and is not affected by temperature
changes.

If your aircraft currently has an external shunt you should order a gauge to match that shunt. Electronics
International manufactures a line of external shunt units (VA-lA-XX, “XX” = shunt value in amps) that will
match any shunt on the market. If your aircraft does not have an external shunt and you elect to install an
external shunt, then order the VA-1A-50 and S-50 shunt (100 amp capability). For aircraft drawing more
than 100 amps order the VA-1A-300 and an S-300 shunt (300 amp capability). Please note: The VA-1A and
VA-1A-50 resolve to .l amp and all other units resolve to l amp. With our digital display, one amp resolution
will still make an excellent electrical diagnostic tool since the current requirements for almost all pieces of
equipment in an aircraft are more than one amp.

Installation

1. Important Information and Initial Check Out:

A. The installer and aircraft owner must read the Warranty before starting the installation.

The installer and aircraft owner must read the Warranty before starting the installation.

The installer and aircraft owner must read the Warranty before starting the installation. There is

information in the Warranty that may alter your decision to install this instrument. If you do not accept

If you do not accept

the terms of the Warranty, do not install this instrument.

B. If you are not an FAA Certified Aircraft Mechanic familiar with the issues of installing aircraft VA

. If you are not an FAA Certified Aircraft Mechanic familiar with the issues of installing aircraft VA

instruments,

instruments, Do Not attempt to install this instrument.

Do Not attempt to install this instrument.

Do Not attempt to install this instrument. The installer should use current aircraft stan-

The installer should use current aircraft stan-

dards and practices to install this instrument (refer to AC 43.13).