KERN NTEP Series Service manual

NTEP/NTNN-IA-defsi-0710
12
GB KERN NTEP/NTNN
Version 1.0 02/2007
Installation Information
Drive-through-scale
Contents
1General Description ........................................................................................ 13
2Standard Configuration and Working Principle............................................ 13
2.1 Major Components...............................................................................................13
2.2 Platform Assembly...............................................................................................14
2.3 Working Principle.................................................................................................14
3Specifications.................................................................................................. 15
3.1 Load Cell ...............................................................................................................15
4Inspection and Site Selection......................................................................... 15
4.1 Inspection..............................................................................................................15
4.2 Site Selection........................................................................................................16
5Installation ....................................................................................................... 16
5.1 Locate....................................................................................................................16
5.2 Installation Procedure..........................................................................................16
6Ramp Installation ............................................................................................ 19
7System Connection......................................................................................... 19
8Technical Data................................................................................................. 20

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1 General Description
Thank you for choosing our NTEP/NTNN series floor scale. The scale consist of new
design ultra-low profile steel platform, four high precision shearing beam load cells.
NTEP/NTNN floor scales have the features of high accuracy, quick weighing and re-
liable weighing performance. The ultra-low platform means less effort required to
manually place the load on the scale. It is suitable to weigh drums, totes, small mix-
ing vats, etc.
The NTEP/NTNN series are designed to provide excellent performance required for
weighing applications in postal distribution centre, distribution centre of commerce,
storage and consignment enterprises, and workshop production line, semi finished or
finished product storehouse of pharmaceutical and food enterprises
2 Standard Configuration and Working Principle
2.1 Major Components
Figure 2-1 Major Components
1 Ramp (Option) 2 Platform
3 Instrument Cable 4 Lifting Eyebolt
5 Connecting Component (ramp) 6 Load Cell
7 Junction box 8 Cover
9 Limit support

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2.2 Platform Assembly
The scales have a channel reinforced platform with two angle steel welding on two
sides of platform. The junction box is mounted on the angle steel. The covers on the
angle steel can be removed to gain access to the junction box. Threaded holes are
provided on two sides of platform. When installing or removing a platform, screw lift-
ing eyebolts into these holes and lift the platform by the eyebolts.
2.3 Working Principle
The elastic body of a load cell deforms under the weight onto the platform. The
Wheatstone bridge bonded to the elastic body loses its resistance balance and out-
puts an analog electric signal proportional to the weight. See Figure 2-2 for the Wiring
Scheme of Floor Scale with four load cells equipped.
Figure 2-2 Wiring Scheme

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3 Specifications
3.1 Load Cell
SBC or SBH shearing beam load cells are provided in all NTEP/NTNN floor scales
with integral 6-conductor, shielded cables (see the table below). The load cell sus-
pension utilizes a rocker pin positioned between the cell and a fixed receiver in the
limit support (see Figure 5-3). The main features of the load cell are:
Recommended Excitation Voltage 6 - 15V (DC/AC)
Maximum Excitation Voltage 20 (DC/AC)
Rated Output 2 ±0.1% mV/V
Non-linearity 0.02% F.S.
Hysteresis 0.02% F.S.
Repeatability 0.01% F.S.
Creep (30 minutes) 0.02% F.S.
Output Terminal Resistance 350 ±1 Ohm
Safe Overload 150% F.S.
Ultimate Overload 250% F.S.
Function Color Code Function Color Code
+ Excitation Green - Excitation Black
+ Signal White - Signal Red
+ Sense Yellow - Sense Blue
Shield Yellow (Thicker)
4 Inspection and Site Selection
4.1 Inspection
Upon delivery of the NTEP/NTNN, visually inspect the scale for any damages which
may have occurred during shipment and handling. Inspect the following areas:
•Platform assembly for any warp.
•Load cell and suspension assemblies.
•Load cell cables.
•Load cell summing junction box.
•Overall platform assembly.
If any damage is found, please contact your freight carrier immediately.

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4.2 Site Selection
Many problems associated with floor scale installations are caused by improper site
conditions. Before installing the scale, check the proposed location for the following
conditions:
•The area where the scale will be located should be level to within 4mm
from the highest to the lowest corner.
•The floor at each corner of the scale must be strong enough to maintain
support throughout the entire weighing capacity of the scale.
•There should be proper drainage away from the scale.
•There should be no heavy vibrations or wind currents at or near the scale.
•The scale should not be subjected to excessive or unusual loading due to
the location or type of equipment used.
If the site is acceptable, proceed with the installation. If not, choose a new location or
select another scale.
5 Installation
5.1 Locate
Place the NTEP/NTNN in the desired location after inspecting the site per Section 4
of this manual.
5.2 Installation Procedure
Place the scale to the ideal location – Pre-install the scale - Remove the platform with
eyebolts – Anchor the limit supports – Reinstall the platform - Route the instrument
cable - Check if installed properly.

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5.2.1 Place Scale
Install eyebolts in the threaded holes provided on two sides of platform. Ensure that
the eyebolts are snug and fully threaded into the holes before lifting. Utilize the lifting
eyebolts when lifting the platform (see Figure 5-1).
Figure 5-1 Scale Lifting
5.2.2 Pre-install Scale
Disassemble the covers on two sides of platform. Place four limit supports under the
load cells, and install the platform. Oscillate the platform to ensure that the rocker
pins are seated in the receivers on the limit support and no binding exists. Place the
ramp at desired side of platform. Connect the ramp and limit supports by connecting
component with M10×15 bolts.
5.2.3 Remove Platform
Attach a chain or strap to the eyebolts, and lift the platform with a forklift or crane.
Take care to keep the positions of limit supports and connecting components.
5.2.4 Anchor Limit Supports
1. Locate the anchor holes in four limit supports. There are a total of 4 anchor
holes (1 per limit support).
2. Drill the anchor holes, using the limit support as a guide. Four M10 self-
expansion bolts are provided with each NTEP/NTNN floor scale for securing
limit supports to floor (see Figure 5-2).
3. All limit supports must bear pressure applied by platform. If the scale is out-of-
level or a limit support doesn’t bear pressure, shimming is required.
4. Secure the limit supports to the floor by installing the anchors and flat head
socket cap screws. The screws are provided with the scale. Be sure to use flat
head screws to maintain clearance between the head of the screw and the
bottom of the deck throughout the weighing range.

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The weighing platform must be aligned with
the use of a water balance.
All foot screws must equally touch the
floor.
5.2.5 Reinstall Platform
1. Clear all debris from the scale area. Ensure that all four load pin receivers in the
limit support are clean and free of foreign material.
Figure 5-2 Top-of-Floor Installation
Figure 5-3 Suspension Details & δ
2. Replace the platform into the limit supports.
3. Oscillate the platform to ensure that the rocker pins are seated in the receivers
and no binding exists.

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5.2.6 Route Instrument Cable
1. A loose coil of instrument cable should be stashed inside the angle steel, on
either side of the junction box assembly.
2. Route the instrument cable under the slot provided in the cover, stopping at
the indicator location.
3. Reinstall the covers on two sides of platform.
6 Ramp Installation (Option)
All model NTEP/NTNN floor scales have a single ramp to accommodate single traf-
fic. Order an optional ramp if dual direction traffic required. Select which side(s) of the
scale platform is to have a ramp attachment.
1. Each ramp is shipped complete with an attachment kit of parts: including four
bolts (M10×15), four washers (10) and four spring washers (10) for connecting
ramp and limit support by connecting component.
2. Insert the M10×15 bolts with washers and spring washers through the holes
on connecting component into the threading holes on limit support and ramp
(see Figure 6-1). Tighten the bolts then (see Figure 5-2).
3. Check to make sure that the ramp is stable and the gap S is between 3 ~ 7mm
(see chap. 5.2.5). Otherwise, shim with ϕ10 washers between limit support
and connecting component to meet this requirement.
7 System Connection
Load Cell Wiring Analog Instrument Cable
Function Color Function Color
+ Excitation Green + Excitation Green
+ Signal White + Signal White
- Excitation Black - Excitation Black
-Signal Red -Signal Red
Shield Yellow(thicker) Shield Yellow/Green
+Sense Yellow
-Sense Blue
Figure 7-1 System Connection DWG

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8 Technical Data
KERN NTEP
600K200M NTEP 1.5T0.5M NTNN 600K200M NTNN 1.5T0.5M
Readability 200 g 500 g 200 g 500 g
Weighing range 600 kg 1500 kg 600 kg 1500 kg
Verification value 200 g 500 g 200 g 500 g
Minimum load 4 kg 10 kg 4 kg 10 kg
Accuracy class III
Dimensions (in mm) 1000 x 1000 x 45
Operating temperature -10°C bis 40°C
Operating humidity 10% ~ 95% relative humidity, non-condensing