Steris SYSTEM 1E, Maintenance Manual

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3-10
764333-675
The outputs to the solid-state relays for S1,
compressor, high-pressure pump, and heater are
not protected by fuses.
3.6.3 Interface Box Assembly
This interface box has an interface board which is used
as a termination point for the input/output unit cables.
Cables run from the interface board to the control
assembly.
The interface box also includes a line filter and a power
supply.
3.6.4 Pressure Transducer
The PT1 transducer is a 0-100 psi range unit, with an
output of 0-100 mV. At 0 psi, the output is 0 mV. The
excitation voltage is 10V dc.
3.6.5 Electrical Description
Refer to machine schematic 10020568.
Incoming power is connected to the CB-1 circuit
breaker. The CB-1 feeds the control transformer,
interface box line filter, and solid-state relays for the
appropriate 115V ac devices. The control transformer
provides 24V ac power. The interface box line filter
feeds the power supply, which pr5, +15, -15
and +12 V dc to the control.
3.7 HIGH-PRESSURE PUMP TEST
ROUTINE
3.7.1 General
The purpose of the HP pump test routine is to check
the function of the HP pump by monitoring the
pressure output of the pump. The control monitors the
LS6 switch for this purpose. LS6 setting is 1.75 psi.
When operating properly, the LS6 switch would be
closed when the pump is ON and be open when the
pump is OFF.
The control monitors the LS6 switch by reading
voltages across the switch. A high reading (5V dc) is
interpreted as switch OPEN, which should be the case
with the HP pump OFF. A low reading (0 VDC) is
interpreted as switch CLOSED, which indicates the
switch is reading a pressure greater than the switch
set-point of 1.75 psi.
The HP pump is checked for proper operation in both
the Liquid Chemical Sterilant Processing Cycle and the
Diagnostic Cycle.
In the liquid chemical sterilant processing cycle, the
HP pump is checked at three points in the cycle. The
first check is just after the seal is inflated. The control
checks LS6, and since the HP pump is OFF at this point,
the switch should be open. The second check takes
place at the Warm/Mix phase. Since the HP pump has
been running at this point, LS6 should be closed. The
third check takes place at the beginning of the second
Rinse drain phase. The HP pump is turned OFF briefly
and the LS6 switch should open at that point.
In the Diagnostic Cycle, the HP pump is checked at
one point in the cycle. At the beginning of the drain
phase, the HP pump is turned OFF and the control
checks LS6 for an open condition. If the test passes, the
HP pump is turned ON and the control checks the LS6
for a closed condition.
3.7.2 Diagnostic HP Pump Test
The control looks at LS6 switch at the end-of-drain test
time phase, the criteria is that LS6 must be
continuously open for a two-second period during a
HP pump OFF test, and must be continuously closed
for a two-second period during a HP pump ON test.
Total time allowed by the control to see a pass/fail
condition is 10 seconds for the pump OFF test and
30 seconds for the pump ON test.
F4 AC3 S3 U41
F5 AC4 S4 U42
F5 AC5 S7 U43
F7 AC6 S2 U44
F8 AC7 Circulation Pump U45
F9 AC8 (Spare U59
F10 AC9 (Spare) U60
Fuse Output Component
Device
Designation