Technical data

Three sight glasses are provided in the oil separator for
monitoring the oil level and verifying performance of the
coalescer element. Liquid oil should be visible in the top
glass of the oil separator when the chiller is off. During
operation, oil may be higher or lower due to system load
and operating conditions.
A low oil level safety switch is provided in the bottom of
the oil separator. A safety shutdown will be initiated if the
oil level is below the switch setting for a 30 second
period after the chiller has been running for 3 minutes.
An oil drain and charging valve is located on the bottom
of the oil separator. A 5/8 inch male flare connection is
provided for draining and charging. Oil can be added
into the oil reservoir with the chiller in service.
A temperature actuated 500 W (115 Vac-1 Ø-50 Hz)
immersion oil heater is located in the oil separator
reservoir to effectively remove refrigerant from the oil.
Power wiring is provided to the control centre.
2.5 Oil Filter
The oil flows from the oil separator through the 3 micron
oil filter. Filtered oil then flows to the oil manifold that is
located at compressor port SB-2.
A dual oil filter housing with isolation valves is standard
on all units. This allows switching between filters and
changing of the off line filter during operation. Units are
fitted as standard with two 3 micron absolute oil filters for
extended compressor life.
2.6 Lubrication
An oil pressure transducer is located at the SB-2
manifold. The differential pressure is measured as the
difference between the oil pressure transducer at SB-2
and the filter pressure transducer located in the oil
separator.
This value is compared to the limits in the control panel
logic. If the oil filter differential reaches 20 PSID, a
warning message is displayed on the control panel, at
25 PSID, a safety shutdown is initiated.
Oil flows from the oil manifold at SB-2 to the plate type,
refrigerant cooled, oil cooler. Cool oil leaving the plate
heat exchanger flows to the eductor block manifold. The
eductor block manifold oil circuit contains the seal oil
pressure transducer and a high oil temperature safety
sensor. The differential pressure between the seal oil
pressure and the evaporator pressure transducer is
calculated and compared by the control panel. If the
differential reaches 20 PSID the control panel will initiate
a safety shutdown. A high oil temperature safety
shutdown will be initiated at 77°C.
The oil leaving the oil eductor manifold block flows into
the compressor at compressor port SB-3 to lubricate the
compressor bearings and shaft seal. The oil injected
into the compressor mixes with refrigerant gas during
compression. The oil and refrigerant gas is discharged
into the oil separator, where it is separated and returned
to the oil sump. A high discharge temperature safety is
located in the discharge line, between the compressor
and oil separator. This safety will initiate a safety
shutdown at 99°C.
2-4 035L02381-GB0
Figure 2.4 Oil Piping