2.10.2.2
Differential Temperature Controller
Differential temperature controller shall be provided with two filled,
remote sensing bulbs connected to the controller by [capillary] [armored
capillary] tubing. Controller shall be direct or reverse acting with
calibrated proportional band and set point adjustments. Controller output
shall be [low voltage electric] [pneumatic] [4-20 mA dc], proportional to
the temperature differential sensed. Provisions for local and remote set
point adjustments shall be included. Range shall be as required to meet
system requirements. For immersion service, thermal wells shall be
provided.
2.10.3
Pilot Lights
Panel-mounted pilot lights shall be NEMA Class 12 oil-tight, push-to-test
transformer for 6-8 Vac lamps. Lamps shall be replaceable by removal of
color cap. Cap color shall be as indicated.
2.10.4
Programmer, Demand Control/Load
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NOTE: Before application of energy management
systems/load shedders to refrigeration systems, and
related fans and pumps, the designer shall ascertain
that application will be neither conducive to
equipment damage nor counterproductive. Safety
trips, compressor slugging, freeze-ups and reloading
of circuits may occur.
**************************************************************************
Programmer shall be fully automatic, fail safe, field programmable,
solid-state, demand control and load programmable for [_____] [16] loads.
Demand control portion shall monitor power consumption by [watt] [or]
[current] transducers. Set point shall be field adjustable with adjustable
dead band. Load shedding sequence time and differential time between load
shedding shall be adjustable. Contacts shall store alarm condition. Meter
readout shall indicate demand deviation from set point. Load profile
recorder shall be strip-chart type with readily discernable event record.
Load programmer shall permit programming of on/off time of each load for
any time element within a week and shall equalize power demand over a
preset time cycle. System shall include input override and time cycle
accelerator for checkout. Alarm condition, status of all loads and time
period shall be visually indicated and recorded. Each load shall include a
H-O-A toggle switch. Alarm provisions shall include relay contacts for
external, remote alarm functions and test provisions. Override
[thermostat] [pressure switch] [timer] shall be provided to restore shedded
loads indicated. Control panel enclosure shall be NEMA ICS 6, Type 1,
surface mounted type with key lock. Load profile recorder shall be
[surface] [flush panel] mounted type. Load relays shall be plug-in type
with critical load failure in "on" mode and contacts rated for pilot duty
at 120 volt ac. Load shedding position switches shall shed loads on a
first shed/last restore basis and remove loads from system logic for
shedding cycle. Time clock shall be fitted with spring motor to maintain
time in event of power failure.
2.10.5
Switches, Fluid Service
Switches shall be field adjustable SPDT type and shall have NEMA ICS 6,
SECTION 15652A
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