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THERMAL
RTD
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A temperature
detecting RTD (resistance thermal detector) is inserted into the
blower's discharge housing to indicate the discharge temperature
of the blower and to provide a signal if the discharge air
temperature reaches a maximum set point. The discharge air
temperature of a regenerative blower operating at full load can
reach 200 to 215 Deg F.
The blower can fail if the
internal temperature of the blower becomes excessive.
Therefore, the RTD not only provides an operating temperature
readout with a digital indicator, but it also prevents excessive
temperature. When a high temperature limit is reached, a
signal is sent to the VFD to shut down the blower and motor to
allow an inspection as to the cause of the high temperature.
High blower operating temperature
can be caused by numerous factors including: overload of the
blower, high
speed or blocked intake air filter.
The RTD provides a 0-10 vdc or
4-20ma output signal that is proportional to temperature.
The settings can be adjusted in the field to meet site
conditions. |
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Standard RTD Specifications
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Temperature
Range
Element
Element Accuracy
Temp Coef (TCR)
Standards
Sheath Material
Excitation Current
Insulation Resistance
Lead Length |
-58
to + 392 Deg F
Platinum 100 Ohm, 500 Ohm, 1000 Ohms at ) Deg C
+/- 0.5% to +/- 0.01% (Multiple DIN, DIN class A & B
Alpha 0.00375 Ohms/Deg C
0.00385 Ohms/Deg C (100, 500, 1000)
0.00392 Ohms/Deg C (100)
DIN 43760, IEC-751, JIS C1604-1989
316 Stainless steel standard, other materials available
1mA or less recommended. 2mA Maximum
At 70 Deg F with all external surfaces dry, the resistance
between leadwire and the sheath is 500 megohms or greater at 250
vdc.
Application dependent
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