1
®
DESCRIPTION
The Fireye 65UV5 flame scanner is a microprocessor based flame scanner utilizing an ultraviolet
tube-type sensor and an electro-mechanical self-checking shutter mechanism. The Fireye 65UV5
flame scanner incorporates an internal flame relay with a fixed ON/OFF threshold thereby eliminat-
ing the need for an external flame amplifier.
The 65UV5 scanner is available with a one-second or four second flame failure response time
(FFRT) depending on the model selected. The “E” versions are one second FFRT, the non-”E”ver-
sions are four seconds FFRT. The Fireye 65UV5-1004, -1004E flame scanner provides an analog 4
to 20 mA output referenced to flame signal strength.
The Fireye 65UV5 flame scanner is powered from a 24 Vdc power source provided externally and
includes an integral 10-foot (3 meter) cable. A color-coded internal LED indicates flame status and
alarm condition. This can be viewed through a viewing port on the rear cover.
The 65UV5 housing has a NEMA 4X / IP66 rating. The unit is suitable for use in Class 1, Div. 2 haz-
ardous environment groups A, B, C & D or Ex II3 G/D Ex nA IIC T4A.
65UV5 CEX models are wired directly via a terminal rail located within the CEX housing. Suitable
glands must be used to terminate the cable at the housing.
Note: The 65UV5-1000, -1000E scanners became obsolete in 2008, and were replaced by the
enhanced capability of the 65UV5-1004 and -1004E scanners.
APPLICATION
Fireye 65UV5 self-checking scanners are used to detect ultraviolet emissions from fossil fuel flames
such as natural gas, coke oven gas, propane, methane, butane, kerosene, light petroleum distillates
and diesel fuels.
PRINCIPLE OF OPERATION
The 65UV5 scanners use a UV-eye detector. This detector is a sealed, gas filled, UV-sensitive tube
containing two electrodes connected to a source of DC voltage. When UV radiation of sufficient
energy falls upon the electrodes, electrons are released and the inter-electrode gas becomes conduc-
tive, resulting in an electric current flow from one electrode to the other. The current flow starts and
ends abruptly and is known as an “avalanche.”
A very intense source of UV radiation will produce several hundred avalanches or pulses per second.
With less radiation there will be fewer pulses per second. Upon total disappearance of flame, the
detector output ceases. Thus, the presence or absence of pulses is an indication of the presence or
absence of flame; the frequency of the pulses is a measure of flame intensity. When the pulses reach
a sufficient level, the internal flame relay is energized.
65UV5 Simplicity
Integrated Flame Scanner
with Internal Flame Relay
CU-104
MARCH 28, 2013
