Lincoln Electric Prism 4, Operator'S Manual

C-5

ACCESSORIES

OPERATION & DIAGNOSTICS 

NORMAL OPERATION DESCRIPTION 
A Prism   with thermal suppression has active protection even 

during a power outage since a discharge of suppressant is 

exclusively dependent on heat induced rupture of the detection 

tubing. The detection tubing is routed through the filter (dirty air) 

side of the filter bank. Intake and exhaust dampers are used to 

contain an event and maximize the effectiveness of a suppressant 

discharge. A smoke detector shuts down the fan motor and closes 

the dampers if smoke or particulate due to bypass of a damaged 

filter is detected in the fan exhaust but this will not trigger a 

discharge since that can only be caused by heat from a thermal 

event. 
B. FAN/DAMPER SHUTDOWN
There are three alarm conditions that will cause the fan to shut 

down and the dampers to close. The first cause is a smoke 

detector alarm, the second is heat induced rupture of the 

detection tubing and third a damper failing to signal that it is open.    
The lower of the two stack lights (on top of the Prism   ) will 

activate on any thermal event alarm and give a pulsed code of the 

type of alarm condition that the unit saw to cause it to shut down. 

A set of pulses followed by a 3 second off time can be decoded 

according to the alarm codes chart. If there are no system 

malfunctions, the dampers close when the fan is turned off. 

Offline cleaning initiated when the fan is shut down will delay 

damper closing until the cleaning is complete.  

C. DISCHARGE NOTIFICATION
Flashing of the Stack Light’s upper high intensity light indicates 

there has been a suppressant discharge. A set of pressure 

switches are contained in a Firetracedual pressure switch box. 

The 195psi normal charge on the detection tubing keeps the 

discharge switch open. A significant loss of pressure caused by 

detection tubing rupture, closes the switch which triggers system 

shutdown and stack light visual notification. 

D. SYSTEM MALFUNCTION ALARMS
The Prism   thermal suppression system monitors important 

functional conditions and provides visual display of any fault by 

flashing a pulsed code on the LED stack light’s lower light. There 

are four coded alarms. 
a. Inlet and exhaust damper alarm. Dampers are closed when the

fan is off but are triggered to open when the fan is started. After

opening, the damper’s actuator switch sends a verification signal

that they are opened. If a signal is not received within 10 seconds,

the fan is shut down and a coded flash of pulses identifies which

damper failed to open.
b. The dual pressure switch box monitors pressure in the red

detection tubing. If the pressure drops too low due to a slow leak,

it trips a pressure switch and flashes a coded pulse on the lower

stack light.
c. The smoke detector alarm triggered by smoke or particulate

bypassing the filters triggers a coded pulse on the lower stack

light.

To allow continued system operation, two of the alarms can be 

temporarily bypassed using the key switch box -the smoke 

detector alarm and low pressure in the detection tubing circuit. 

Note the important caution statements listed in the 

troubleshooting section. Damper alarms can not be bypassed 

since they must be open for the fan to move air through the unit. 

The discharge alarm can not be bypassed either since the cause 

of this alarm must be resolved and the system reconditioned prior 

to additional use. Bypass mode is identified when the lower light 

on the stack light is solid red.  

F. RESOLVING ALARMS
Identify the alarm using the “Prism   Stack Light Alarm Codes” 

table, then use the troubleshooting section to resolve alarm codes. 

When you have any alarm with a coded pulse on the stack light’s 

lower light, there are some ways the controls are helpful to assist 

in troubleshooting. The signals for damper open switch, discharge 

switch input, service pressure switch input, smoke detector input 

are all digital IO inputs into modules that have LED lights 

indicating the status of that input. These are located next to the 

M12 cable connection for the module. Use the system wiring print 

to make sure cables are connected to the correct IO module input. 

Damper feedback function can be verified by manually moving a 

damper (black button is a clutch on the damper actuator) and 

watching the LEDs on the module to confirm the input is “seen” 

by it. 
It is possible to have multiple alarm conditions, but only one code 

can flash at a time. Resolving one and clearing it will allow the 

flashing of any unresolved alarm conditions. Resolving all alarms 

must be completed before the controls will allow a normal startup. 

DISCHARGE, RECOVERY AND MAINTENANCE 

A. INSPECTION
In the event of a discharge of the thermal suppression system, all 

components of the system must be inspected and any damaged or 

compromised components replaced. Un-ruptured red detection 

tubing can be reused only if there is no evidence of heat damage. 

That also applies to interior detection tube fittings containing 

internal seals that can be compromised by exposure to high heat. 

The suppressant tank has a pressure gauge that should show zero 

after a discharge. It will need to be re-charged or replaced. If there 

is any evidence of high heat exposure on any system components 

they must be replaced.  

B. REPLACEMENT
For quick repair, it is advisable to keep a stock of red detection 

tubing along with a spare suppressant tank. Replacement parts 

can be ordered through Lincoln Electric. Detection tubing is the 

heart of the system and special attention should be made to 

replace it with the same lengths/routing/locations. Altering from

the factory installed method can affect the systems ability to

properly react to any future thermal event. The suppressant tank

can be re-charged by the manufacturer instead of discarding it.

Contact the Lincoln Electric Service Department to aid in

indentifying a certified Firetrace distributor. 

E. ALARM ACKNOWLEDGE/BYPASS CONTROL

PRISM

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