Evoqua Wallace&Tiernan 50-200 Series, Manual

Page: 38 / 111

50-200 EVAPORATOR FOR CHLORINE
WT.050.200.001.UA.IM.0814
27
EVOQUA W3T98237
rine liquid. If a blockage develops or a valve is closed while chlorination is
stopped, the pressure will increase substantially. Normal operating pressure
is 30 to 140 psi. If the pressure rises into the 180 to 200 psi range, take
corrective action. Refer to the Troubleshooting guide, Symptoms Group
2, in Section 4. The pressure gauge is designed for exposure up to 600 psi
without loss of calibration.
• WATER TEMPERATURE METER: The meter indicates the water bath tem-
perature. Normal operating temperature is approximately 180°F.
• CONTROL BOX ALARM LIGHTS: The front of the control box contains three
alarm lights and one power indicator light. The red HIGH TEMPERATURE
alarm lights will go on when the water bath temperature exceeds 200°F.
The orange LOW TEMPERATURE alarm light will illuminate when the water
bath temperature drops below 160°F. If the water level drops below the
bottom of the sightglass, the red LOW WATER LEVEL alarm light will come
on.
NOTE: When the evaporator is turned on after short-term shutdown and the
water is at normal operating level, the LOW WATER LEVEL alarm light will
remain on for several seconds. Then the circulating pump will turn on. This
pause is a part of the normal control operations of the evaporator.
• CATHODIC PROTECTION AMMETER: Refer to paragraph 3.1, Preparation For
Initial Operation. The meter may not indicate current for the first several
months of service. Normal operating current is between 50 and 250 milli-
amps. If it exceeds this value, it may be reduced by turning counterclockwise
the knob located to the right of the milliammeter. If the current is allowed
to rise above 250 milliamps, the anodes of the cathodic protection system
will not last as long as they would if the reading is maintained. The 50- to
250-milliamps reading assures full protection. More than 250 milliamps
unnecessarily consumes anodes.
• WATER LEVEL SIGHTGLASS: The sightglass provides a direct indication of
water bath level. If a LOW WATER LEVEL alarm light or separate alarm actu-
ates, observation of the sightglass will confirm the low level condition or
indicate a low water level switch malfunction. The normal operating level
in the sightglass tube, as maintained by the automatic water level control,
is 2/3 to 3/4 full. Low water level is approximately 1/8 full or less.
• OBSERVATION OF NEED FOR CYLINDER CLEANING: A build-up of impurities
in the evaporator cylinder will result in gradual loss of heat transfer and
loss of evaporating capacity. An obvious indication of this will be a cooling
of the pipe coming from the outlet of the vacuum regulator-check unit (or
gas pressure reducing valve). This cooling can be sensed by touching the
pipe or observing condensation of frost on the outlet pipe.