9 install the shunt – Electronics International CGR-30P User Manual

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B. Monitoring a Signal that is Switched to Ground:

Monitoring a Signal that is Switched to Ground:

EDC

Temp or Resistive Fuel

Level Channel.

Bus

Load

VI-221

Device, Switch or

Relay

If a Load does not exist,
an additional VI-221
must be placed in the
circuit as shown. This
provides a pullup for the
switch.

Light, Horn, etc.

2.8 Install the CO Detector, G-Sensor and/or Other Available CGR Options:

The CO Guardian Remote Mounted CO Detector, G-Sensor and other CGR options listed on EI’s price sheet are
provided with there own installation instructions. These items should be installed and wired in accordance with the
accompanying instructions. Note: The CO Detector connects to Port 4 or Port 3 Input on the CGR.

2.9 Install the Shunt:

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. It is not affected by temperature changes.
If your aircraft currently has an external shunt you can calibrate your CGR to that shunt. The CGR can be
calibrated to match any shunt on the market.

A. Determine How the Shunt will

Determine How the Shunt will

be Installed in the Aircraft’s

be Installed in the Aircraft’s
Electrical System:

Electrical System:

There are two common methods of
installing a shunt in an aircraft. One
method is with the shunt in the
alternator lead. The other method is
with the shunt located in the battery
lead. The S-50 shunt that comes with
the CGR-30 package may be installed
using either method. The advantages
and disadvantages of each method are listed below.

There are few disadvantages with either method. Although EI’s test pilot has a slight preference for
the alternator lead when using the CGR, ease of installation should be the determining factor in this
installation. If more than one shunt is required, a second shunt can be installed through a FM-VA-M-
(50 or 300) Functional Module. The Functional Modules come with their own installation instruc-
tions.

Installation Method

Advantages

Disadvantages

Battery Lead:

1. Shows load current on the

ground (engine off) and during

an alternator failure.

2. All Warning Lights are
operational.

1. Cannot show load current during

flight or when the engine is running.

Alternator Lead:

1. Shows load current during

flight or when the engine is
running.

2. All Warning Lights are
operational.

1. Cannot show load current when

the engine is off or during an

alternator failure.

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