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Each time you press 

I

, load correction will ensure you get the 

exact load requested. Load correction can be enabled and 
disabled from 

OPTIONS

.

• 

Load can be removed at any time by pressing the red 

O

 

key.

The first 

TEST

 instrumentation page shows the real-time Voltage 

and Frequency in large fonts, together with the power in kVA, cos 

φ

 and kW. Along the top, the Status line shows that we are in 

MANUAL

, and 4 minutes and 32 seconds has elapsed since the 

last load accept. The selected load is displayed on the top right of 
the status line.

Use this page when initially adjusting the AVR and governor 
settings.

6. View the Instrumentation

• 

Press 

PAGE

 to change to the next instrumentation page. 

After four presses of 

PAGE

 you will be back to page one.

The next two 

TEST

 pages shows all the true rms three phase 

measurements of Voltage (V), Frequency (Hz), Current (A), 
Power (both kW and kVA) and Power Factor (Cos 

φ

).

The second and third instrumentation pages provide all the 
electrical data required when full-load testing. Displayed on 
the right are the voltage and frequency; below each are the 
maximum and minimum values for the last load change.

Note that page two shows line-line voltages, whereas page three 
shows line neutral voltages.

The fourth 

TEST

 page provides a graphical view of the voltage 

and frequency when the last load was applied.

The voltage and frequency graphs display the first 6 seconds of 

the last load change, as a percentage of the supply voltage and 
frequency rating.

Use this page when testing governor and AVR transient response.

7. Using Automatic Load Control

At any time you can change between manual and automatic 
load control.

• 

Press 

AUTO

 for automatic load control. Press F2 again to 

return to 

MANUAL

.

• 

A pre-programmed sequence of up to 16 loads can set 
up by pressing the 

EDIT TEST

 key.

Again, use the 

+

 and 

 keys to change the selected value. Press 

SELECT

 to select either %, cos 

φ

 or time.

Pressing 

NEXT

 moves down to the next line. You can press 

COPY

 

to copy the selected value down to the next line.

• 

Press 

OK

 to exit 

EDIT TEST

.

• 

Pressing the green l key will start the sequence.

• 

Load can be removed, and the automatic sequence stopped, 
by pressing the red 

O

 key.

The status of the automatic test is shown on the right of the 
status line.

Any sequence that is running will be paused if 

MANUAL

EDIT 

TEST

 or 

SETTINGS

 are pressed. Pressing I will restart a paused 

load sequence.

Whilst the test is running the 

+

 and 

 keys can be used to 

quickly override the selected load. Press I to apply the new 
load selected.

Froment

Sigma IHT Version 4 - Quickstart Guide

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