Parker ELL-1 Manual

ELECTRONIC LIQUID
LEVEL CONTROL
Type ELL-1, ELL-2 and ELL-3
FOR AMMONIA, R-12, R-22, R-502
FEATURES
• Level indicated by Digital Read Out and Bar Chart
Display (LED)
• Calibration not affected by loss of power
• Up to five separate switching functions
• Field-replaceable relays, with 10 amp contacts
• Mix and Match Controller and Probe Assemblies
• Potted Probe Circuit Board
• 120/240 V, 60 Hz or 110/220 V, 50 Hz Power
• Refrigerant Temperature range:
-150° to 212° F (-100° to 100° C)
• Maximum Rated Pressure for Probe Assembly:
450 psig (31 bar)
• No moving mechanical parts
• 4-20 ma Output Signal
• Water resistant Q/D (Quick Disconnect) at Probe
Fig.1
Refrigerating Specialties Division
050342
BULLETIN 61-20D
February 1996
Installation, Service and Parts Information
Description
The Type ELL Electronic Liquid Level Control consists of four parts: a
Controller, a Probe Assembly, an Interconnecting Cable and a Pipe
Column Fitting. (See Fig. 1) There are three versions: ELL-1 for one
control level, ELL-2 for one control level plus one high and one low
level auxiliary switching operation, and ELL-3 for one control level
plus two high and two low levels of auxiliary switching operations.
The Probe Assembly measures a change in capacitance due to the
changing liquid level and the Controller converts this into an electrical
signal which then operates a self-contained relay(s).
All adjustments for level set-points are made at the Controller which
is installed remotely from the Probe Assembly. The liquid level is shown
on the face of the Controller by means of a Digital/Bar Graph Display
which is calibrated from 0 to 100 per cent of the active probe length.
The probe which is available in six different lengths will work with
R-717, R-12, R-22 or R-502, The interconnecting cable between the
Controller and the Probe Assembly can be as long as 5000 ft. (1524
M), although when purchased as a complete package with controller
and probe, a 30 ft. (11 M) cable will be supplied.
Purpose
The Type ELL Electronic Liquid Level Control is used to provide
electrical switching action in response to a change in refrigerant liquid
level. The point(s) of level control action are remotely adjusted. This
device can be used with refrigerants R-717, R-12, R-22 or R-502. It is
not effected by specific gravity. It may be used with liquid temperatures
in a range of -150° to 212°F (-100° to 100°C).
One Type ELL can replace as many as five Type LL Float Switches on
a vessel. It can be used to control and maintain the liquid level in
flooded surge drums, flooded shell and tube chillers, high and low
pressure receivers, intercoolers, transfer vessels and various kinds
of accumulators, including recirculating (liquid overfeed) types.
The Type ELL can also be used to activate or deactivate electrical
controls, to energize or de-energize magnetic starters controlling
1
I S O 9 0 0 1
Type ELL
C E R T I F I E D