FIREYEDESCRIPTION AND INSTALLATION

IMPORTANT NOTE

The information provided in this bulletin is directed to competent boiler and combustion service

technicians who are experienced in the installation and operation of Fireye Flame Safety equipment.

Persons not familiar with Fireye products should contact the nearest Fireye representative or other

qualified service group.

The 45UV5 scanners as well as all other Fireye scanners, are designed to be used exclusively with

the appropriate Fireye Flame Safeguard and Burner Management controls. The application of these

scanners to other than Fireye equipment should be reviewed for approval by Fireye.

APPLICATION

Fireye 45UV5 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. 

These 45UV5 models are used only with the Flame-Monitor, BurnerLogix, D-Series, FlameWorx,

MicroM and some P-Series Fireye control models to provide flame safeguard and monitoring systems for supervised manual, semi-automatic and fully automatic single burner boilers, process ovens

and heaters.

PRINCIPLES OF OPERATION

The 45UV5 scanners use a UV-eye detector. This detector is a sealed, gas filled, UV-sensitive tube

containing two electrodes connected to a source of AC voltage. When UV radiation of sufficient

energy falls upon the electrodes, electrons are released and the inter-electrode gas becomes conductive, 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. Pulses generated by the

scanner are transmitted to a compatible Fireye control via scanner wiring.

FEATURES

The components are contained in a cast aluminum housing sealed with an oil-resistant gasket. The

quartz lens is a planoconvex design, resulting in increased sensitivity. Also included in the scanner is

an electromagnetic shutter that permits a self-checking circuit to verify that the scanner and signal

circuits are producing valid flame presence or absence information. During the shutter closed period,

the detector’s optical path is blocked from flame radiation, allowing the amplifier control to verify

the proper operation of the ultraviolet tube. While the shutter is open, flame presence or absence is

detected. The resultant scanner output (while flame is detected) is a continuous, periodically interrupted, pulsed flame signal which is a prerequisite for energizing the associated Fireye control’s

Flame Relay.

1. AN ACCEPTABLE SCANNER LOCATION MUST ENSURE THE FOLLOWING:

— Reliable pilot flame detection.

— Reliable main flame detection.

— Rejection of pilot flame too short or in the wrong position to ignite the main flame reliably,

thus prohibiting main fuel admission.

NOTE: Reliable signals must be obtained at all air flows and furnace loads (ranges of fuel firing).

2. If combustion air enters the furnace with a rotational movement of sufficient velocity to deflect

pilot flame in direction of rotation, position the scanner 0 to 30 degrees downstream of the pilot

burner and close to the periphery of the throat where the ultraviolet radiation is at a maximum.

(See Figure 4).

3. Having determined an appropriate location for the sight tube, cut a clearance hole for a 2 inch

pipe through the burner plate. If register vanes interfere with the desired line of sight, the interfering vane(s) should be trimmed to assure an unobstructed viewing path at all firing levels, see

Figure 3.

4. Mount scanner sight pipe by either:

— Centering a Fireye No. 60-1664-3 (NPT) or 60-1664-4 (BSP) swivel mount over the hole

and installing the sight pipe on the swivel mount, 

or 

— Inserting the end of the sight pipe into the hole, aligning the pipe to the desired viewing

angle and tack welding. (Welding must be adequate to temporarily support the weight of the

installed scanner). The sight pipe should be arranged to slant downward so that the dirt and

dust will not collect in it.

When a satisfactory sighting position has been confirmed by operational test, (see section on

alignment), the sight pipe should either be firmly welded in place or, if the swivel mount is used,

the base position should be secured by tightening the three hex head cap screw located on the

swivel mount ring. In certain older style swivel mounts, tack welding may be required.

6. Excessive flame signal can affect flame discrimination and prevent the control connected to the

scanner from performing properly. To reduce the signal level of the tube, or improve flame discrimination, orifices may be installed to decrease the scanner’s field of view and reduce its sensitivity. Installation of the orifice disk is shown in Figure 6.

7. The scanner viewing window must be kept free of contaminants (oil, smoke, soot, dirt) and the

scanner temperature must not exceed its maximum rating. Both requirements will be satisfied by

continuous injection of purge air.

The scanner mounting may be made with provision for purge air through the 3/8” opening as shown

in Figure 6, Item A or C, or through a 1" tee/wye connection as shown in Figure 6, Item B. Normally

only one of the two connections is provided with purge air and the other is plugged. When a Fireye

coupling is used as shown in Figure 6, the 1" tee/wye connection is used for the purge air (plug 3/8”

opening).

Under normal temperature conditions, with clean burning fuels and moderate ambient temperature

conditions, purge air flow of approximately 4 SCFM (113 L/min) is generally adequate. A 0.1 psig

positive pressure difference between the atmosphere and boiler pressure measured at right angle to the

purge air flow, should result in a purge air flow of 4 SCFM. Up to 15 SCFM (425 L/min) may be

required for fuels that may produce high levels of smoke of soot or for hot environments to maintain

scanner internal temperature within specifications.

NOTE: The maximum viewing field of the lens is one inch per foot. Do not use more than one foot of

one inch sight pipe. Increase sight pipe diameter one inch for every additional foot of sight pipe

length used, to avoid restricting the scanner’s field of view. Temperature in the scanner housing

should not exceed those temperature limits listed in the specifications. Excessive temperatures will

shorten scanner life.

CAUTION: Ultra-violet tubes can simulate flame when exposed to high levels of “X” and GAMMA

radiation. The table below indicates the maximum dose of radiation that a UV tube can be exposed to

safely.

SCANNER WIRING

All FIREYE controls are protected against short-circuited scanner input terminals. The following

recommendations apply for scanner control wiring:

• Keep scanner wiring as short as possible.

• Use wires rated for scanner voltage and its ambient conditions (temperature, humidity, oil resistant, flame retardant, etc.)

• Do not run scanner wires in the same conduit as other electrical wires.

• Avoid wire loops and poor groundings.

• Keep high voltage ignition wires well away from scanner wires.

The 45UV5 self-check scanner has four 6 foot (1800mm) leads:

45UV5-1005 & 1105:

Two black leads which power the shutter from the associated control and two red leads which drive

the UV tube and carry the flame signal to the control amplifier.

45UV5-1006, 1007 & 1009:

Two black leads which power the shutter via L1 & L2 and two red leads which drive the UV tube

and carry the flame signal to S1 & S2 on the control.

If it is necessary to extend the scanner wiring, the following instructions apply:

Scanner wires should be installed.in a separate conduit. The wires from several scanners may be

installed in a common conduit.

45UV5-1006, 1007, 1009.

1. Selection of wire

— Use #14, 16, or 18 wire with 75 C, 600 volt insulation for up to 100 foot distances (signal

loss approximately 20% at 100 feet).

— Asbestos insulated wire should be avoided.

— Multiconductor cable is not recommended without prior factory approval.

— Extended Scanner Wiring. For extended scanner wiring up to 1500 feet, and for shorter

lengths to reduce signal loss, use a shielded wire (Belden 8254-RG62U) coaxial cable, or

equal for each red wire of the 45UV5. The ends of the shielding must be taped individually

on both ends and not grounded.

For multiple burner installations:

2. Distances are decreased when more than one set of scanner leads are installed in a common conduit. For example, the maximum distance for 2 scanners is 750 feet and for 3 or more scanners

the distance decreases to 500 feet.

3. High voltage ignition wiring should not be installed in the same conduit with flame detector

wires.

WARNING: DO NOT CONNECT 45UV5 SCANNERS IN PARALLEL

45UV5-1005, 1105

1. Up to 25 foot conduit run. 

— Use #18 AWG or heavier, 600V 90C minimum rated wire, installed in conduit.

2. Over 25 to 300 feet maximum:

— Use #18 AWG or heavier, 600V, 75C rated wire for the two black leads (shutter).

— Extended Scanner Wiring. For extended scanner wiring up to 1500 feet, and for shorter

lengths to reduce signal loss, use a shielded wire (Belden 8254-RG62U) coaxial cable, or equal

for each red wire of the 45UV5. The ends of the shielding must be taped individually on both

ends and not grounded.

For multiple burner installations:

3. Distances are decreased when more than one set of scanner leads are installed in a common conduit. For example, the maximum distance for 2 scanners is 750 feet and for 3 or more scanners the

distance decreases to 500 feet.

4. High voltage ignition wiring should not be installed in the same conduit with flame detector wires.

ALIGNMENT AND ADJUSTMENTS

The following procedures are recommended to ensure optimum flame detection and discrimination.

Flame discrimination is the ability to see only one burner or one pilot with other burners or pilots operating nearby. These procedures should be used whenever parts are replaced, when the scanner has been

moved, when the flame shape is altered (additional fuels, new burners, burner/register modifications)

as well as on all new installations.

Pilot Flame Scanner

1. Apply power to scanner and associated control.

2. Start pilot.

3. Adjust scanner sighting to detect pilot flame in the manner shown in Figure 4.

4. When flame is properly sighted, the flame signal should correspond to the acceptable ranges indicated in the appropriate bulletin for each compatible FIREYE control. If readings fluctuate widely,

readjust scanner sighting until highest, steadiest reading is obtained.

5. Spark Rejection Test: When the proper signal reading has been obtained, make sure that the scanner and the associated control do not respond to the ignition spark. This is accomplished by cutting

off the fuel to the pilot and attempting to start the pilot using the spark igniter. If the system

responds to the spark, the sighting should be realigned.

Minimum Pilot Test

This test assures that the flame detector will not detect a pilot flame too small to reliably light off the

main flame. The test should be made on every new installation, scanner replacement, and following

any repositioning of the flame detector. THE MINIMUM PILOT TESTS MUST BE ACCOMPLISHED BY A TRAINED AND QUALIFIED BURNER TECHNICIAN.