Nassar EN-3P User manual

SINCE 1973
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User Manual
LIQUID LEVEL
CONTROL RELAY
MODEL EN-3P

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EN-3P LIQUID LEVEL CONTROL RELAY
Features
ŸControls Level of Conductive Liquids in
Pump Up (Fill) or Pump Down (Drain)
Applications.
ŸAdjustable Sensitivity from 5K to 100K
ohms.
ŸDual Voltage 120 or 220 VAC Supply.
ŸLED Status Indication.
ŸProtects Pumps from Dry Running.
The EN-3P is a dual-probe conductive liquid level
control designed to monitor the levels of conductive
liquid and control the actuation of pumps or valves to
regulate levels. It is also suitable for protecting
submersible pumps against dry running or protecting
tanks from an"overflow". This device can also be used
to control dosing of liquids in mixing processes and to
protect heating elements in the event of non
immersion.
The sensitivity can be adjusted within the range of
5KΩ to 100KΩ by rotating the knob on the unit. This
sets the level at which the relay determines whether
liquid is present at the probe or not.
The EN-3P is dual voltage, it can be used with either
120 or 220 VAC.
Description
Voltage supply
To use a 220 VAC voltage supply use the terminals T1
and T3. To use a 120 VAC voltage connect the supply to
terminals T1 and T2. After the supply voltage is
connected the green LINE LED will turn ON.
Operation
220 VAC 120 VAC
T1 T1T3 T3T2 T2
PUMP DOWN (DRAIN) APPLICATION
The relay energizes when the liquid level comes in
contact with the high probe (PH) and remains
energized until the liquid level falls below the lower
probe (PL). To use this application place a wire
between terminals F/D and PC.
F/D PC
PUMP UP (FILL) APPLICATION
The relay energizes when the liquid level falls below
the low probe (PL) and remains energized until the
liquid level comes in contact with the high probe (PH).
To use this application leave terminals F/D and PC
disconnected.
PUMP DRY RUNNING PROTECTION
To protect the pump from dry running use the same
connections as the Pump Down (Drain) application
and connect the contact between NO and C in series
with the pump starter control.
F/D PC
F/D PC
SENSITIVITY ADJUSTMENT
To adjust the sensitivity within the range of 5KΩ to
100KΩ rotate the knob on the unit. This sets the level
at which the relay determines whether liquid is
present at the probe or not. For water it’s
recommended to set the sensitivity adjustment at 50K
Ω . To set the sensitivity follow the next procedure:
SENSITIVITY
75K
100K
5K
50K
25K
DANGER!
Potentially hazardous voltages are present. Electrical
shock can cause death or serious injury.
Installation should be done by qualified personnel
following all National, State & Local Codes.
BE SURE TO REMOVE ALL POWER SUPPLYING THIS
EQUIPMENT BEFORE CONNECTING OR
DISCONNECTING THE WIRING.
READ THE INSTRUCTIONS BEFORE INSTALLING OR
OPERATING THIS DEVICE.
KEEP THIS MANUAL FOR FUTURE REFERENCE.

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EN-3P LIQUID LEVEL CONTROL RELAY
NO CNC PL
PH
T1 F/D T3 PC T2
RELAY
LINE LH
SENSITIVITY
75K
100K
5K
50K
25K
LED Indicators
LINE: Supply voltage connected.
Relay: Output relay is closed.
H: The high probe (PH) is
submerged in the liquid.
L: The low probe (PL) is
submerged in the liquid.
Typical example of connection
C NC
NO P H P L
PC
T1
L1 L2
T2 T 3
F/ D
L1
CB
L2
PUMP
DIRECT OPERATION WITHOUT AN EXTERNAL STARTER
Only for single phase pumps
220 VCA
CNC
NO P H P L
PC
PUMP
T1 T2 T3 F/D
OPERATION WITH A STARTER
OL
CB
OL
OL
SW
L1
L1
L3 L1 L3
L3
L2
OL
M
M
M
M
220 VAC
M = Contactor
= Overload Relay OL
SW = Switch
CB = Circuit Breaker
1) Use cable size 12 to 18 AWG to wire the probes.
2) Use 3 different cable colors to prevent a mixup with the
probes.
3) The probe PC should not be more than 8 inches below
from probe PL.
4) The probe PH should not be more than 48 feet higher
than probe PL.
Probe installation
PC
PL
PH
PROBE CABLES
PROBE
CABLE
BRONCE
PROBE
TIGHTENING
SCREW
HIGH
PROBE
LOW
PROBE
COMMON
PROBE
Install the probes in the liquid deposit. If the probes
aren’t submerged in the liquid and their LED
indicators are turned ON, then increase the sensitivity
level until they are turned OFF.
Submerge the probes in the liquid and check if their
LED indicators are turned ON. If the probe LED
indicators aren’t turned ON, decrease the sensitivity
level until they are.
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EN-3P LIQUID LEVEL CONTROL RELAY
Testing the EN-3P
If the EN-3P is not operating correctly please follow the next
steps to verify if the installation is correct:
1.- Connect the 120 VCA voltage supply to terminals T1 and
T2, the green LINE LED should turn ON. Use a wire to
connect terminal F/D with terminal PC.
120VCA
NO CNC PL
PH
T1 F/D T3 PC T2
RELAY
LINE LH
SENSITIVITY
75K
100K
5K
50K
25K
NO CNC PL
PH
T1 F/D T3 PC T2
RELAY
LINE LH
SENSITIVITY
75K
100K
5K
50K
25K
NO CNC PL
PH
T1 F/D T3 PC T2
RELAY
LINE LH
SENSITIVITY
75K
100K
5K
50K
25K
If the EN-3P operated correctly when following this steps,
but continues experiencing problems with the operation it
indicates that the problem is not the EN-3P. The problem
comes from the installation or an issue with the wiring,
common issues with the installation or wiring include:
A.- A bad connection with the cables.
B.- A bad connection with the probes.
C.- The liquid resistance is too high (above 100K ohms).
3.- Connect terminals F/D, P/C and PL with terminal PH. The
H (High Probe) LED and the red RELAY LED should turn ON
and the output contact between NO and C should be closed.
Use a multimeter to measure the continuity between NO
and C to make sure the contact is closed.
2.- Connect terminals F/D and P/C with terminal PL, the L
(Low Probe) LED should turn ON.
120VCA
120VCA
Dimensions
in (mm)
1.77(45)
3
(77)
4.44(113)
4.68 (119)

EN-3P LIQUID LEVEL CONTROL RELAY
WARRANTY
THESE PRODUCTS ARE WARRANTED TO BE FREE FROM DEFECTS IN WORKMANSHIP OR MATERIAL UNDER NORMAL SERVICE AND USE FOR A PERIOD OF
THREE (3) YEARS FROM DATE OF MANUFACTURE. NASSAR ELECTRONICS SHALL, AT ITS OPTION, REPAIR OR REPLACE F.O.B. POINT OF MANUFACTURE
THE PORTION OF THE PRODUCT FOUND BY NASSAR ELECTRONICS TO BE DEFECTIVE. ALL REPLACEMENTS OR REPAIRS NECESSITATED BY INADEQUATE
MAINTENANCE, NORMAL WEAR AND USAGE, UNSUITABLE POWER SOURCES OR ENVIRONMENTAL CONDITIONS, ACCIDENT, MISUSE, IMPROPER
INSTALLATION, MODIFICATION, REPAIR, USE OF UNAUTHORIZED REPLACEMENT PARTS, STORAGE OR HANDLING, OR ANY OTHER CAUSE NOT THE FAULT
OF NASSAR ELECTRONICS ARE NOT COVERED BY THIS LIMITED WARRANTY, AND SHALL BE AT THE BUYER'S EXPENSE. ALL COSTS OF DISMANTLING,
REINSTALLATION AND FREIGHT, AND THE TIME AND EXPENSES SHALL BE BORNE BY THE BUYER.
LIMITATION OF REMEDY AND LIABILITY
NASSAR ELECTRONICS SHALL NOT BE LIABLE FOR DAMAGES CAUSED BY DELAY IN PERFORMANCE. THE REMEDIES OF THE BUYER SET FORTH IN THIS
AGREEMENT ARE EXCLUSIVE. IN NO EVENT, REGARDLESS OF THE FORM OF THE CLAIM OR CAUSE OF ACTION (WHETHER BASED IN CONTRACT,
INFRINGEMENT, NEGLIGENCE, STRICT LIABILITY, OTHER TORT OR OTHERWISE), SHALL NASSAR ELECTRONIC'S LIABILITY TO THE BUYER AND/OR ITS
CUSTOMERS EXCEED THE PRICE TO THE BUYER OF THE SPECIFIC GOODS MANUFACTURED OR SERVICES PROVIDED BY NASSAR ELECTRONICS GIVING
RISE TO THE CLAIM OR CAUSE OF ACTION. THE BUYER AGREES THAT IN NO EVENT SHALL NASSAR ELECTRONIC'S LIABILITY TO THE BUYER AND/OR ITS
CUSTOMERS EXTEND TO INCLUDE INCIDENTAL, CONSEQUENTIAL OR PUNITIVE DAMAGES. THE TERM “CONSEQUENTIAL DAMAGES” SHALL INCLUDE,
BUT NOT BE LIMITED TO, LOSS OF ANTICIPATED PROFITS, REVENUE OR USE AND COSTS INCURRED INCLUDING WITHOUT LIMITATION FOR CAPITAL, FUEL
AND POWER, AND CLAIMS OF THE BUYER'S CUSTOMERS.
Specifications
PROBE VOLTAGE
PROBE CURRENT
LIQUID RESISTANCE SENSITIVITY
MAXIMUM PROBE CABLE LENGTH
MAXIMUM POWER CONSUMPTION
CONTACT RATING
DIRECT OPERATION CONTACT RATING
OUTPUT CONTACT LIFE
WEIGHT
VOLTAGE SUPPLY
22 V DC
0.36 mAmp. DC
Adjustable from 5K to 100K ohms.
1000 feet (300m)
3 Watts
NO 12 Amp. , NC 8 Amp.
1.5 HP Max. @ 220 V, 3/4 HP Max. @ 120 V.
10,000,000 Max. , 200,000 at direct operation.
14 ounces (392g)
120/220 V AC ± 10% 50/60 Hz
*Specifications subject to change without notice.
Nassar Electronics
J. M. Salas 124 Pte.
64290 Monterrey, N. L. México
email: [email protected]
Ph.+ 52 (81)-8351-0006