MAINTENANCE WITH Q&A
Page 5-18
The input voltage label says 230 VAC (or 208 VAC). I thought I had 220 VAC. Is that OK?
208V and 230V are NOT the same. 220V is a misnomer in the United States—there is no such standard as nominal
220V in the United States though 220V does exist in Europe . You must verify the exact type of electrical service you
have. If there is any doubt, you must consult with a qualifi ed electrician who is familiar with industrial plant wiring. In
addition, the input line voltage should be measured while the chamber is operating in the COOL mode to ensure that
the expected nominal voltage of either 208V ±5% or 230V ±5% is present.
Why doesn’t the chamber come with a power cord and plug?
Most local and national electrical codes require permanent wiring for this type of equipment. If used as a portable
device, a fl exible wire with a plug may be acceptable, but local and national codes may limit the length to 6 feet.
Cincinnati Sub-Zero recommends that the appropriate method for your installation be determined by a qualifi ed
electrician who is familiar with industrial plant wiring.
Why does my chamber heat or cool slower than the published specifi cations?
Performance is signifi cantly effected by the characteristics of your test sample. Factors include size, weight, material,
shape, and power dissipation if energized. The test sample should be placed in the chamber in a manner that allows
for air circulation. You should not place the test sample directly on the chamber fl oor. It should be placed on the shelf.
Multiple test samples should be distributed throughout the chamber to ensure even airfl ow and minimize temperature
gradients. If necessary, additional shelves should be used to evenly distribute the load.
How can I modify the chamber to cool faster?
Unfortunately, there is little you can do to improve upon the designed-in performance. Cincinnati Sub-Zero does offer
an LN2 boost package that can be installed in the fi eld to increase cooling performance.
Why is there water/ice/snow in the chamber?
Any time the ambient air is subjected to temperatures below the dewpoint, moisture will condense out of the air. The
effect is ice or frost during low temperature operation. When the chamber is heated above 0°C, the ice or frost will turn
into water. To avoid moisture condensation, make sure the port plugs are inserted at all times. Also, avoid opening the
chamber door while the chamber is operating at temperatures below room ambient. When a low temperature test is
completed, warm the chamber to at least room ambient before opening the chamber door and before removing your
test sample.
How accurate is the chamber?
That’s a loaded question! There is no “chamber accuracy” specifi cation as such. The answer requires an
understanding of several performance parameters.
Control Tolerance – The control sensor is located in the discharge airfl ow. Control tolerance is a measure of how
much the temperature varies after stabilization at the control sensor. It is a measure of the relative variations, NOT
the absolute accuracy of the readout. The control tolerance specifi cation for this chamber is ±0.5°C, or a total of 1°C.
For example, the temperature set point may be -65.0°C. The actual temperature varies between -64.5°C and -65.5°C.
These specifi cations are for an empty chamber. The addition of a test sample may effect the control variations. In
some instances, the test sample will reduce these variations.
Uniformity – Also known as Gradients. This is a measure of variations in temperature at different locations
throughout the chamber interior, at the same time, after stabilization. The uniformity specifi cation can vary for each
chamber. These specifi cations are for an empty chamber. The addition of a test sample may effect the temperature
uniformity. For example, an energized test sample will produce a higher temperature near the sample. For more
specifi c uniformity information please contact CSZ.
Why do I smell something when I operate the chamber for the fi rst time at high
temperatures?
Cincinnati Sub-Zero chambers are cleaned and polished before leaving the factory. Stainless steel polish can give off
an odor while at elevated temperatures. This is a temporary condition and is non toxic.
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