SAB 202 regulator

[Den123]

Hi, guys.
Maybe someone worked with the compressors SAB 202 SM with auto VI, (-40/+35, NH3 with economiser).
How controller set a starting capacity slide position?
I do not understand the way of regulation mode with two slide VI and capacity,
A current calculated value of zero point a differ every start, or it change?

[RANGER1]

Dan123,
0% capacity never alters, only 100% changes with Vi slide position, which is worked out by Unisab.
Vi I would have thought would not change with your conditions.

[mbc]

HI
file is to big to send it
give your mail I'll mail it to you

it is 1.4M

[Den123]

My mail is alf931@yandex.ru,
I have read a manual for Unisab 3 and for SAB 202 compressor unit.
Here is describe of part load capacity and full load capacity, but what is value of start zero position must be and how it calculate?
For long time i work with Howden WRV, XRV series compressors with manual VI on 2980 rpm motor drive. I install VI by rotating of regulation screw depending diagram once before first start, calibrate capacite sensor. Here is simple way to suction pressure control: suction raise than capacity raise, suction low if capacity low and compressor can work long time on any capacity from 10% to 100%. Here is no zero position that must be installed by controller.
But Sabroe is another way capacity control, is it correct that i understand:
compressor start, capacity slide goes to variable zero set point,stay on this position? , than capacity goes to 100%.After that Vi slide goes to 2.2 and to 4.5 (100%) during 2 min if suction pressure approx 0 bar. When suction pressure decrease, Vi smoothly goes to min position 2.2. After that capacity slide goes to variable zero position, and compressor stops. Is it really trye?

[mbc]

hi

it has reg valve with on and off time for raining capacity
check your mail
I sent it .
https://files.acrobat.com/a/preview/a6d241b4-ed4f-4a1f-b833-8569528de0d7

[mbc]

hi

it has reg valve with on and off time for raising capacity 1518215183

[Den123]

Thanks very match, i will check my mail.

[Den123]

And i really do not understand about slide/VI indicator on front side of compressor. On compressor there are two slide sensors: GT 8 with scale capacity and for VI position GT 9 without any scale. By front scale i can see only current calpacity slide position or Vi slide too? A pointer rotate clockwise or counterclockwise?

[RANGER1]

Please read this, see if helps.

http://www.mayekawa.com.au/wordpress/wp-content/uploads/2010/12/V-series-Screw-Compressor.pdf

[Den123]

Thanks, Ranger1, now i have enough for understanding. During the unit start i'll see the working features and write here.