Emerson 20/20 Manuel D’Utilisation

1 – 1

Figure 1-1. Operational Flow Charts (1 of 2)

Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 1.8.5153

Section 1 • Operational Flow Charts

Volume and 
Capacity slides are 
less than 5%

Oil Separator Temp 
>Oil Sep Start Trip 
Setpt

Filter Diff Press < 
Start Filter Diff Trip 
Setpt

Oil Pump On: Prelub Oil Press is > Prelub Oil
Press Reset Setpt for “Min Compressor Prelub Timer” 
setting (typically 5 seconds)

Start Compressor

Start 

Compressor

Is

Run Oil Press>

Prelub Oil Press

Reset setpt?

(Default 5 PSI)

Is

Run Oil Press>

Run Oil Press

Reset setpt?

(Default 40 PSI)

“Oil Press

Bypass at Comp 

Start” timer

expires (60 sec 

after start)

Run Oil Press Failure

Run Oil Press Failure

“Filter Diff Press Safety

Changeover” timer expires 

(60 sec after start)

Is Filter Diff >

Hi Filter Diff Press Run

Trip Setpt

for 5 seconds

Oil Separator Temp
Safety Changeover
Timer expires (5 min 
after start)

Is

Oil Sep Temp > Lo

Oil Sep 

Run Reset

setpt?

Run

Run Filter Diff Press Failure

Lo Run Oil Sep Temp Failure

Is

Motor Amps >

FLA (ON)

Setpt?

Is

Dsch Press >

Cutin (ON)

Setpt?

Is

Dsch Press >

Cutout (OFF)

Setpt?

Capacity Increase
Disabled

Capacity Decrease
until Amps < FLA x 
1.0625

Normal Loading and 
Unloading

Is

Motor Amps >

FLA (OFF)

Setpt?

Capacity Increase
Disabled

Capacity Decrease until 
Dsch Press < ON Setpt x 
1.0625

Normal Loading and 
Unloading

No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

No

No

No

No

No

No

Requirements to Start Compressor

Critical Compressor Run Logic at Compressor Start

Compressor Amperage Load Limiting

High Discharge Pressure  Load Limiting