070.550-IOM (JUN 2016)
Page 15
NGC GAS ROTARY SCREW COMPRESSOR
INSTALLATION
OPERATION AND START-UP INSTRUCTIONS
The Johnson Controls - Frick NGC Rotary Screw Compressor
will be a component in an integrated system. As such the
compressor requires some specific operation and conditions
to ensure trouble-free running.
The information in this section of the manual provides the
logical step-by-step instructions to properly start up and
operate the NGC Rotary Screw Compressor in your Unit.
Only matters which may influence the proper operation of
the NGC compressor are included.
WARNING
THE FOLLOWING SUBSECTIONS MUST BE READ AND
UNDERSTOOD BEFORE ATTEMPTING TO START OR
OPERATE THE UNIT.
COMPRESSOR HYDRAULIC SYSTEM
(24 VDC Solenoid valves and distribution block are
available as sales order option)
The compressor hydraulic system (See Figure 12) actuates
the movable slide valve (MSV) to load and unload the
compressor. It also actuates the movable slide stop (MSS) to
increase or decrease the compressor’s volume ratio (VI).
The hydraulic cylinder located at the inlet end of the NGC
compressor serves a dual purpose. It is separated by a fixed
bulkhead into two sections. The MSV section is to the left of
the bulkhead and the MSS is to the right if you are facing the
right side of the compressor. Both operations are controlled
by double-acting, four-way solenoid valves, which are
actuated when a signal from the appropriate microprocessor
output energizes the solenoid valve.
SINGLE-ACTING MODE - High Stage
Open valve at SC1
Close valve at SC2
Open valve at BP (bypass)
Figure 12 - Hydraulic Schematic
Operation
