Parker PLLC Service manual

Refrigerating Specialties Division 1
Programmable
Liquid Level Controller
Type PLLC
For use with ITP Depth Tracker transducer
liquid level probe
Purpose:
The Programmable Liquid Level Control provides remote
liquid level management for industrial refrigeration. The
PLLC is designed for use specifically with Parker's ITP
Depth Tracker transducer liquid level probe. The PLLC
provides the power source for the current loop of the
ITP. The ITP probe is used to provide a current signal
proportional to the vertical liquid level in a standpipe or
vessel. The PLLC serving as a switching mechanism also
converts the return signal and performs up to 5 program-
mable relay functions.
Bulletin 61-50B
Type PLLC
October 2006
Installation Information
309317
Keypad Programmable Level Setting Procedure
• Supply power to the PLLC. All 4 digits will light for a
second then count down 1-4 from left to right. If there is
no level in the vessel or the probe is disconnected, the
display should read 00
• Push the "Channel" button once. The LED will display
the Channel, Mode (Relay Disposition) and the Actual
Level Set-point.
• Use the "Up" and "Down" arrow keys to select the set-
point for this level.
• Press the "Enter" key, you will hear a BEEP that will
confirm your setting.
• Channels 1, 4, and 5 are programmed using the same
procedure.
• Channel 2 is capable of operation as an additional
differential level control or it can be set to operate an
alarm function.
• Differential Level Control: Follow the same procedure
used in setting channel 3.
• Alarm: In order for Channel 2 to be used as an alarm,
a differential must be set using the High and Low level
settings of this channel.
• Push the Channel button on the keypad until Channel
2 and Mode L is displayed. Using the arrow keys, set
the low level to represent 2% of Full Scale (Full Scale =
100%) lower than the actual level setting required and
press the enter key.
• Example: If 80% is required for Channel 2 setpoint, set
the channel 2 Low setting for 78%.
• Push the channel button again to display Channel 2
and Mode H. Now set the High Level setting required
for this channel and press Enter.
• Note: 2% is the smallest value that can be en-
tered. Larger differentials can be used to allow high
liquid levels in the vessel to return to a safe operating
Wiring:
The separable terminal blocks on the PLLC will accom-
modate up to 14 gage wire. The Line Voltage Input can
be either 120/240V 60Hz or 110/220V 50Hz. The PLLC
provides the power source for the current loop of the
transducer probe. The programmable relays are indi-
vidually 5 amp fused. Relays are equipped with normally
open and closed terminals and can be wired as either.
The maximum recommended distance between PLLC and
probe is 5000 ft.
Fig.1
CHANNEL 1 HIGH RED
CHANNEL 2 LEVEL CONTROL
CHANNEL 3 LEVEL CONTROL
CHANNEL 4 LOW GREEN
CHANNEL 5 LOW RED
ISO 9000 - 2 0 0 0 CERTIFIED
STRAIN RELIEF
1" CONDUIT KNOCKOUT
PLLC

Refrigerating Specialties Division 2
condition. This will prevent rapid repeat alarms due to
equipment failure.
• Channel 2 and 3 (Level Controls)
• The Level Control channels require a "Low" and a
"High" level setting.
• Push the "Channel" button on the keypad until the
Channel "2 or 3" and mode "L" (Low Level) is displayed.
Using the arrow keys, make your Low Level setting.
Press the "Enter" key, a "BEEP" will confirm your entry.
• Push the "Channel" button again. The "Mode" LED will
change from "L" to "H" (High Level). Again, using the
arrow keys, make your High Level setting, press the
"Enter" key and a "BEEP" will confirm your entry.
Programmable Relay Disposition
• Channels 1, 4 and 5 have programmable relay disposi-
tions. Channels 1 default to "H" (High Level), 4 and 5
default to "L" (Low Level).
• First select the channel by pressing the "Channel" but-
ton on the keypad. Pay special attention to the letter
displayed on the "Mode" LED.
• Press the "Mode" key on the keypad. You will see the
displayed letter change from and "H" to an "L". Press-
ing the key again will return the "H" on the "Mode" LED.
• Select the Mode. If you started with an "H" displayed,
select the "L" to change the relay disposition.
• Use the "Up", "Down" keys to select the level for the
channel.
• Press the "Enter" key. You will hear a BEEP to verify
your entry. You will also notice the LED for the chan-
nel will light-up or turnoff depending on the disposition
selected.
Level Test Mode: 2 Modes Available
(With Relays De-energized & Energized)
First Mode: Display responds, relays maintain their dis-
positon. Second Mode: Both relays and display respond
to confrim control circuits.
First Mode
• First scroll through the channels by pressing the
"Channel" button on the keypad until a single "t" is
displayed in the "Channel" segment of the LED.
• Press the "Mode" key on the keypad. A second "t" will
appear in the "Mode" segment of the LED.
• Push the "Up", "Down" arrow key's on the keypad to
simulate a level change. The LED's on the right will
light-up or go off (depending on the relay disposition
selected) as the channel set-point is passed. The 4-20
mA output will also change while simulating a level
change.
Second Mode
• To test the level settings and relay function, follow the
same procedure for the De-energized Test Mode to the
point where "tt00" is displayed on the LED.
• Using the "Up" arrow key, scroll through the channel Fig. 2
ITP Probe Installed In Standpipe
ITP Probe
R/S Standpipe Cap
Globe Valve with
Horizontal Stem
Level Column
Sight Glasses
Globe Valve with
Horizontal Stem
Weld
Optional Oil Drain
settings one at a time. After each set-point is passed,
press and hold the "Enter" key for about 5 seconds. The
"tt" segments will flash and you will hear the relay en-
ergized or de-energized depending on the relay disposi-
tion.
• Note: Caution should be used during this procedure to
prevent Alarms and Equipment Shut Downs.
2445 S.25th Ave Broadview Ill 60155
T708-681-6300 F708-681-6306