The meter shall indicate safe intensity, low intensity, and
unsafe intensity by means of color codes on the meter face, or
have a 0 to 100 percent scale. The UV intensity meter shall be
clearly labeled and located on the remote control panel.
c.
A nonresettable elapsed time meter shall be provided per bank of
lamp modules. The meter shall record hours of UV bank operation
from 0 to 99,999 hours.
d.
One hand/off/auto switch shall be provided for each UV bank and
for each automatic slide gate shown and specified.
e.
Alarms shall be time delayed to prevent nuisance alarms.
2.3.6.4
Minor Alarms
Minor alarms and dry contacts shall be provided to indicate that
maintenance attention is required. Minor alarms shall include:
a.
Low warning UV intensity.
b.
Individual lamp failure.
2.3.6.5
Major Alarms
Major alarms and dry contacts shall be provided to indicate an extreme
condition in which the disinfection performance may be jeopardized. Major
alarms shall include:
a.
Low UV intensity.
b.
Lamp failure of 2 or more adjacent lamps.
c.
Multiple lamp failure.
d.
Module failure.
2.3.6.6
Flow Pacing
**************************************************************************
NOTE: If the system consists of 2 or more banks of
lamps, the system can be flow-paced using a signal
from an effluent flow monitoring device in the plant.
**************************************************************************
a.
A flow pacing system shall be provided to turn the UV banks on and
off in relationship to the signal received from the plant effluent
flowmeter. Flow pacing sequence shall be as recommended by the UV
equipment manufacturer. Where lamp dimming is used, a controller
shall be provided to allow plant operator to ratio the flow to UV
dosage and UV intensity. Where on/off control is used, the system
shall allow the operator to vary the flowrate setting and allow
the operator the option to operate individual banks in either the
manual or automatic mode. Logic and time delays shall be provided
to regulate the UV bank ON/OFF cycle to prevent excessive cycling
on both startup and shutdown of the UV bank. Multicycle lamps may
be specified in applications which demand up to 100,000 annual
cycles.
b.
Normal mode of operation shall place each effluent channel
continuously in service.
SECTION 11376
Page 18