HARVEY Chemiclave EC5500, Service Manual, Page: 14 / 56

14
P
RINCIPLES OF
O
PERATION
Note
Exposure conditions are maintained
until the control knob is set to depres-
surize.
Exposure
This timed function begins when chamber pressure reaches
20 psig (138 kPa). Pressure switch is then energized. The
timer counts down the exposure time of 20 minutes. The
decimal point flashes when the timer is active. Chamber
pressure is displayed continually on the pressure gauge. If
pressure goes below 20 psig (138 kPa), the pressure
switch is de-energized. This stops the timer countdown and
the flashing decimal point until pressure returns to 20 psig
(138 kPa) or above.
Exposure Complete
When the exposure is complete, the timer displays “00” and
a tone sounds. The COMPLETE indicator lights. The
PURGE indicator flashes briefly (see Figure 9).
Depressurization
Begins when the operator sets the control knob to DE-
PRESSURIZE (see Figure 4). This vents the chamber
through the metering valve to the condensate tank (see
Figure 8, DEPRESSURIZE mode). Pressure switch is de-
energized. The COMPLETE indicator stays on. The
PURGE indicator continues to flash as the chamber
depressurizes for one minute.
Purge
Begins automatically after Depressurization (approximately
1 minute delay before pump starts). See Figure 10. Timer
displays “07” (EC5500) or “09” (EC6000). The COMPLETE
indicator goes out. The PURGE indicator lights. Purge
pump forces sterilant vapor from the chamber until the timer
counts down to “00.”
Complete
After Purge, the pump stops and the PURGE indicator goes
out. A tone sounds. The pressure gauge reads less than 2
psig (14 kPa). The cycle is complete. The COMPLETE light
stays lit for one minute, then goes out. Heater remains
controlled as long as the POWER switch remains ON. The
POWER indicator is lit and he TEMP indicator cycles on
and off with the heater. To unload, the operator opens the
door (see Figure 11).