Eschmann T-20 Service manual
T20-a
OPERATION TABLE
Service manual
111707
T-SM47j
Preliminary
Information
Technical data
Technical
description
Read these Instructions before use
Keep these ‘Instructions’ in a safe convenient place for future reference. Read in conjunction
with the Publications detailed in Section 1.1.
Eschmann After Sales Service Department
Safety notes
Maintenance
Part removal
adjustment
replacement
The Eschmann After Sales Service Department is staffed and equipped to provide advice and
assistance during normal office hours. To avoid delays when making enquiries, please quote the
Model and Serial Number of your Operation T able which is shown on the Serial Number plate, the
location of which is shown below. Please ensure you include all alpha and numeric digits of the
Serial Number.
The Serial Number
plate is located here
For further information visit www.eschmann.co.uk
All correspondence relating to the after sales service of Eschmann Equipment to be addressed to :
UK Customers
Eschmann Equipment, Peter Road, Lancing, West Sussex BN15 8TJ, England.
T el: +44 (0) 1903 765040. Fax: +44 (0) 1903 875711.
Overseas Customers
Contact your local distributor. In case of doubt contact Eschmann Equipment.
Patents and Trade marks
The ESCHMANN name and logo are registered trade marks of Eschmann Holdings Limit ed.
“Eschmann Equipment” is a trading name of Eschmann Holdings Limit ed.
“T20-a” is a trade mark of Eschmann Holdings Limited .
Patents : Worldwide Patents Pending.
Copyright © 2005 Eschmann Holdings Limited
All rights reserved. This booklet is protected by copyright. No part of it may be reproduced, stored in a
retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying,
recording or otherwise without written permission from Eschmann Holdings Lim ited.
The information in this publication was correct at the time of going to print. The Company, however,
reserves the right to modify or improve the equipment referred to.
The CE marking affixed to the product certifies that it complies with the
European Medical Devices Directive 93/42/EEC and related legislation.
T-SM47j July 2005
Service manual
T20-a
OPERATION TABLE
CONTENTS
1.0 Preliminary information
1.0 Preliminary information . . . . . . . . . . . . . . . . . . . 5
2.0 Technical data
2.1 Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3 Movements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.4 Table loading . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.5 Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.6 Classification and symbology . . . . . . . . . . . . . . 9
2.7 Use in conjunction with other equipment . . . . . . 9
2.8 Standards compliance . . . . . . . . . . . . . . . . . . . . 9
2.9 Environmental conditions . . . . . . . . . . . . . . . . . . 9
3.0 Technical description
3.1 Power supply assembly . . . . . . . . . . . . . . . . . . 13
3.2 Control electronics . . . . . . . . . . . . . . . . . . . . . . 13
3.2.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.2.2 Handset overview . . . . . . . . . . . . . . . . . . . . 14
4.0 Safety warnings
4.1 ‘Service position’ . . . . . . . . . . . . . . . . . . . . . . . 16
4.2 Lifting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.3 M10 trunk screw removal . . . . . . . . . . . . . . . . 16
4.4 Trend and tilt actuator removal . . . . . . . . . . . . . 16
4.5 Working with mains voltage . . . . . . . . . . . . . . . 16
4.6 Gas springs . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.7 Hot parts on PCAs . . . . . . . . . . . . . . . . . . . . . 16
4.8 Biological contamination . . . . . . . . . . . . . . . . . 16
4.9 Connection of leads . . . . . . . . . . . . . . . . . . . . . 16
4.10 Leaking batteries . . . . . . . . . . . . . . . . . . . . . . . 16
5.0 Maintenance
5.1 Power supply assembly . . . . . . . . . . . . . . . . . . 17
5.2 Table fault finding . . . . . . . . . . . . . . . . . . . . . . . 17
5.2.4 Break motion control . . . . . . . . . . . . . . . . . 17
5.2.5 Trunk section connector blocks . . . . . . . . . 17
5.3 Fuse location . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.4 Service schedule and safety check . . . . . . . . . 18
6.0 Part removal/adjustment/
replacement
6.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.2 Table base and column covers . . . . . . . . . . . . 20
6.2.2 Base covers . . . . . . . . . . . . . . . . . . . . . . . . 20
6.2.2.1 Removal of base covers . . . . . . . . . . 20
6.2.2.2 Replacing base covers . . . . . . . . . . . 21
6.2.3 Access to column . . . . . . . . . . . . . . . . . . . . 21
6.2.3.2 Lower column access . . . . . . . . . . . . 21
6.2.3.3 Lower-mid column access . . . . . . . . 21
6.2.3.4 Upper-mid column access . . . . . . . . 21
6.2.3.5 T op of column access . . . . . . . . . . . . 23
6.2.4 Telescopic covers . . . . . . . . . . . . . . . . . . . . 23
6.2.4.1 Removal of telescopic covers . . . . . . 23
6.2.4.2 Refitting the telescopic covers . . . . . 23
6.2.5 Bellows . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6.2.5.1 Removal of the bellows . . . . . . . . . . . 23
6.2.5.2 Replacing the bellows . . . . . . . . . . . . 24
6.3 Table base components . . . . . . . . . . . . . . . . . . 24
6.3.2 Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6.3.3 Pedal dampers . . . . . . . . . . . . . . . . . . . . . . 24
6.3.4 Front wheels . . . . . . . . . . . . . . . . . . . . . . . . 25
6.3.5 Castors . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
6.3.5.1 Castor assembly . . . . . . . . . . . . . . . . 25
6.3.5.2 Castor wheels . . . . . . . . . . . . . . . . . . 25
6.3.6 Brake pads . . . . . . . . . . . . . . . . . . . . . . . . 25
6.3.7 Castor pillar bushes . . . . . . . . . . . . . . . . . 29
6.3.8 Pedal spindle bushes . . . . . . . . . . . . . . . . 29
6.3.9 Lifting roller assembly.. . . . . . . . . . . . . . . . 29
6.3.10 Pedal catch block . . . . . . . . . . . . . . . . . . . 29
6.3.11 Pedal anti-skid pads . . . . . . . . . . . . . . . . . 29
6.3.12 Pedal catch pawl and spring . . . . . . . . . . . 29
6.4 Table column components . . . . . . . . . . . . . . . . 30
6.4.2 Trendelenburg actuator . . . . . . . . . . . . . . . . 30
6.4.3 Tilt actuator . . . . . . . . . . . . . . . . . . . . . . . . . 30
6.4.4 Telescopic column assembly . . . . . . . . . . . . 30
6.4.5 Tilt & Trendelenburg motor . . . . . . . . . . . . . . 32
6.4.6 Tilt bush . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6.4.7 Trendelenburg bush . . . . . . . . . . . . . . . . . . . 32
6.4.8 Bearing pads . . . . . . . . . . . . . . . . . . . . . . . . 32
6.5 Table sections . . . . . . . . . . . . . . . . . . . . . . . . . 33
6.5.1 Head and leg section . . . . . . . . . . . . . . . . . 33
6.5.1.1 Guide pins . . . . . . . . . . . . . . . . . . . . 33
6.5.1.2 Gas springs . . . . . . . . . . . . . . . . . . . 33
6.5.1.3 Top cover . . . . . . . . . . . . . . . . . . . . . 33
6.5.1.4 Gas spring release head/pin . . . . . . . 33
6.5.1.5 Gas spring release handle . . . . . . . . 35
6.5.1.6 X-ray translucent top . . . . . . . . . . . . 35
6.5.2 Trunk sections . . . . . . . . . . . . . . . . . . . . . . . 35
6.5.2.1 Traverse motor . . . . . . . . . . . . . . . . . 35
6.5.2.2 Traverse drive belt . . . . . . . . . . . . . . 36
6.5.2.3 Break motor . . . . . . . . . . . . . . . . . . . 36
6.5.2.4 Break gearbox . . . . . . . . . . . . . . . . . 36
6.5.2.5 Side rails . . . . . . . . . . . . . . . . . . . . . 39
6.5.2.6 Top covers . . . . . . . . . . . . . . . . . . . . 39
6.5.2.7 Push button components . . . . . . . . . 39
6.5.2.8 Traverse rod bearing . . . . . . . . . . . . . 39
6.5.2.9 Drive belt guide bearing . . . . . . . . . . 41
6.5.2.10 Attachment blocks . . . . . . . . . . . . . . 41
6.5.2.11 Black tops . . . . . . . . . . . . . . . . . . . . 41
6.6 Electrical components . . . . . . . . . . . . . . . . . . . 41
6.6.2 Three actuator PCA . . . . . . . . . . . . . . . . 42
6.6.3 Four actuator PCA . . . . . . . . . . . . . . . . . 42
6.6.4 Infrared receiver PCA . . . . . . . . . . . . . . 42
6.6.5 Power supply assembly . . . . . . . . . . . . . 43
6.6.6 Traverse motor . . . . . . . . . . . . . . . . . . . . 43
(continued over page)
T -SM47j P3/54
6.6.7 Break motor . . . . . . . . . . . . . . . . . . . . . . 43
6.6.8 Tilt and Trendelenburg motors . . . . . . . . 43
6.6.9 Telescopic column assembly . . . . . . . . . 43
6.6.10 Break potentiometer loom . . . . . . . . . . . 43
6.6.11 Tilt potentiometer loom . . . . . . . . . . . . . 43
6.6.12 Trendelenburg potentiometer . . . . . . . . . 43
6.6.13 Height potentiometer loom . . . . . . . . . . . 43
6.6.14 Traverse motor loom & m’switches . . . . . 45
6.6.15 Connector blocks & looms . . . . . . . . . . . 45
6.6.16 Switch & accessory panel looms . . . . . . 45
6.6.17 Column energy chain and loom . . . . . . . 45
6.6.18 Break gearbox loom . . . . . . . . . . . . . . . . 46
6.6.19 Batteries, table & handset . . . . . . . . . . . 46
6.6.20 Fuses . . . . . . . . . . . . . . . . . . . . . . . . . . 46
6.6.21 Table infrared code change . . . . . . . . . . 46
6.6.22 Infrared handset code change . . . . . . . . 46
6.6.23 Handset service . . . . . . . . . . . . . . . . . . . 47
6.6.24 Processor PCA . . . . . . . . . . . . . . . . . . . 47
6.6.25 Standby panel and loom . . . . . . . . . . . . 47
6.6.26 Battery management reconditioning . . . . 47
6.7 Function tests . . . . . . . . . . . . . . . . . . . . . . . . . 47
6.7.1 Batteries . . . . . . . . . . . . . . . . . . . . . . . . 47
6.7.2 Battery charger . . . . . . . . . . . . . . . . . . . 47
6.7.3 Corded handset . . . . . . . . . . . . . . . . . . . 47
6.7.4 Infrared handset . . . . . . . . . . . . . . . . . . . 47
6.7.5 Footswitch control . . . . . . . . . . . . . . . . . 47
6.7.6 Standby control panel . . . . . . . . . . . . . . 47
6.7.7 Sections (head and leg) . . . . . . . . . . . . . 47
6.7.8 Base pedals . . . . . . . . . . . . . . . . . . . . . . 48
6.7.9 Cycle of movements . . . . . . . . . . . . . . . 48
6.8 Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Figures
1.0 Identification of main parts . . . . . . . . . . . . . . . . . 6
2.1 Major dimensions and movements . . . . . . . . . . 10
2.2 Maximum patient weights . . . . . . . . . . . . . . . . 11
2.3 Maximum patient weights . . . . . . . . . . . . . . . . 12
3.1 Schematic diagrams . . . . . . . . . . . . . . . . . . . . 15
6.1 Table covers general arrangement . . . . . . . . . . 22
6.2a T able base general arrangement (ext’l catch) . . 26
6.2b T able base general arrangement (int’l catch) . . . 27
6.2c T able base general arrangement (int’l catch
and increased height) . . . . . . . . . . . . . . . . . . . . 28
6.3 Table column general arrangement . . . . . . . . . . 31
6.4 General arrangement, head & leg section. . . . . 34
6.5 Table long trunk general arrangement . . . . . . . . 37
6.6 Table short trunk general arrangement . . . . . . . 38
6.7 Table traverse general arrangement . . . . . . . . . 40
6.8 Table base main electrical components . . . . . . 42
6.9 Handset button functions and serial labels . . . . 4 4
6.10 Old and new infrared Handset buttons . . . . . . . 44
A1 T20-a Schematic diagram - Base Section . . . . 51
A2 T20-a Schematic diagram - Pedestal Section . . 52
A3 T20-a Schematic diagram - Trunk Section . . . . 53
Appendix 1
Torque conversions . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Appendix 2
Application software guide . . . . . . . . . . . . . . . . . . . . . 50
Appendix 3
T20-a Table schematics . . . . . . . . . . . . . . . . . . . . . . . 51
Appendix 4
Electrical safety checks . . . . . . . . . . . . . . . . . . . . . . . 54
P4/54 T-SM47j
T20-a
OPERATION TABLE
1.0 PRELIMINARY INFORMATION
WARNING
Before servicing this operation table the
engineer should be familiar with all the
warnings and cautions contained within the
‘Instructions for use’ detailed in section 1.1.
This service manual does not provide details
of how to operate the table nor does it provide
information on the symbols and warning signs
provided on the table. All this information is in
the ‘Instructions for use’ supplied with the table.
Additional copies of the ‘Instructions for use’
can be obtained from Eschmann Equipment.
Only qualified and trained engineers should
service or maintain this operation table to
ensure that all the built-in safety features are
not compromised.
1.1 This Service Manual should be referred to for details
of the T20-a Powered Operation Table, Serial Number (SN)
T2AA3A0000 or above:
REF T20-223-2301* & T20-108-2301*
REF T20-221-2301 & T20-106-2301
REF T20-221-2101 & T20-106-2101
* These models have Denyer style accessory side rails.
The related publications listed below provide additional
information.
T-IM102 (1 11701) - Instructions for use
T-IPL35 (111706) - Illustrated parts list
T-IM94 (11 1012) - ‘T’ Series Application software manual
T-IM56 (698907) - General accessory leaflet
The number in brackets above, is the part number for that
publication.
1.2 ‘Instructions for use’ and ‘Service manuals’ should
be readily accessible for reference prior to and when
operating, cleaning, servicing, or, maintaining the operation
table.
1.3 The table and all accessories are not supplied sterile
therefore the table and all accessories should be cleaned
and disinfected in line with hospital practice and the
information supplied in the ‘Instructions for Use’ before use.
1.4 The manuals listed above and the Application
software, are available to order from Eschmann Equipment,
see inside front cover for address details.
1.5 Make sure that routine servicing is carried out as
detailed in the service schedule, section 5.4, by Eschmann
trained or accredited engineers.
1.6 The service schedule provided in this manual details
a program of maintenance work to be carried out at six
monthly intervals, refer to the applicable section of this
manual for details of how to perform these various functions.
Any special adjustments required for components are
detailed in the part replacement (section 6.0) for that item
to save duplication. As routine the Service Schedule should
be followed in the event of an additional service due to a
fault developing with any aspect of the table, this will ensure
that all aspects of the table are covered.
WARNING
Ensure that the correct screw torque settings
are used as detailed within this manual to
ensure safety and that parts are not damaged.
1.7 Throughout this manual there are recommended
torque settings for many of the screws. In the main, these
are only provided on the illustrations. Ensure that these
are checked and the correct torque settings are used where
specified. These are provided to ensure safety (i.e. screws
are tightened correctly) and that components are not
damaged by excessively high torques.
1.8 Fig. 1.0 identifies the main parts of the T20-a
operation table.
1.9 The table can be placed into a ‘Service Position’ that
provides easy access to components within the ‘top of
column’ area (ensure table is switched ‘off’ before opening
top). To achieve this position first note the safety warning
in section 4.1. Remove as much as possible from the table
top (e.g. leg and head sections, accessories and
mattresses etc.). Remove the top of column steel covers
(items 13 and 14 of Fig. 6.1). Remove the four M10 screws
(each side) that secure the trunk sections to the pedestal
(not the M6 cap head screws that can be seen passing
through the oilite bushes on each side) and allow the trunk
section to pivot (short trunk down) about the oilite bush
pivots (item 16, Fig. 6.3). Extreme care should be taken at
all times with the table in this position, especially during
transition into and out of the ‘Service Position’. Use tool
number T2203 to maintain contact between the connector
blocks if required when the table is in the ‘Service Position’.
When returning the table out of the ‘Service Position’ ensure
the eight M10 screws are tightened to the correct torque
and that the covers are replaced.
1.10 The ‘Instructions for use’ (provided with the table)
contain all the cleaning, disinfection and care instructions,
consult this for these aspects as they are not duplicated in
this manual.
CAUTION
Continued use of the table batteries when
‘critically low’ can damage the batteries. Charge
batteries regularly to maintain peak
performance. Do not remove the table from
charge until both charging LED’s are ‘green’ to
avoid false battery level indication on the
handset.
T -SM47j P5/54
NOTE: The table illustrated has external pedal locking catches. Some
tables have internal locking catches, see section 6.2 and 6.3 for details.
Fig. 1.0 Identification of main parts
P6/54 T-SM47j
T20-a
OPERATION TABLE
Key to Fig. 1.0
1 Head section
2 Long trunk section
3 Short trunk section
4 Leg section
5 Leg section gas spring
6 Short trunk section release button
7 Long trunk section release button
8 Battery fuses
9 Wheel foot pedal
10 Head section release bar
11 Head section gas spring
12 Standby control panel
13 Base
14 Pedestal
15 Castor foot pedal
16 Leg section release bar
17 Mains fuses
18 Connection socket for mains (ONLY use Eschmann mains cord, Part No. 391177)
19 Main battery charging state LED:
Red = Mains ‘on’, batteries in ‘bulk’ charge
Amber = Mains ‘on’, batteries in ‘top-up’ charge (duration 2 hours)
Green = Mains ‘on’, batteries in ‘trickle’ charge (i.e. fully charged)
20 Standby battery charging state LED (colour code as main battery above)
21 Main table ‘On/Off’ switch ( = Of f, = On)
22 Connection socket for Eschmann footswitch (ONLY)
23 Table ‘On’ LED (green)
Bright = Table in use, micro-controllers active
Dim = T able ready for instant use but in battery save (sleep) mode
24 Connection socket for Eschmann handset (ONLY)
25 Head and leg section end blocks (use to stow UK handset)
26 Accessory side rails (can also be used to stow handset*)
27 Standby battery switch
* Clip on handset must match side rail type, see ‘Instructions for Use’.
Note: For location of the Serial Number plate see inside front cover.
T -SM47j P7/54
2.0 TECHNICAL DATA
2.1 Weights
2.4 Table loading
See maximum patient weight distribution charts in Fig. 2.2
and 2.3 for various table positions and orientations.
The nominal weights of the standard table components
are listed below (for 50mm mattresses):
Leg section (without mattress) .. .. 11.50kg
Leg section mattress .. .. .. .. 2.75kg
Head section (without mattress) .. .. 7.75kg
Head section mattress .. .. .. 2.00kg
T able (base and column only) .. 192.00kg
Long and short trunk assembly* .. 55.75kg
Long and short trunk mattress .. .. 7.25kg
T otal weight standard table .. .. .. 279kg
Lightweight leg section.. .. .. .. 4.50kg
Footrest (incl. mattress) .. .. .. 7.00kg
Width extender (incl. mattress) .. .. 6.00kg
Perineal instrument tray .. .. .. 3.00kg
* (without mattress)
2.2 Dimensions
The following are the nominal major dimensions of the
standard table (with head and leg sections fitted) and
include the 50mm mattress and side rails if applicable (see
Fig. 2.1 for illustration, the number in brackets after the
item details which part):
Overall length (2) .. .. .. 2102mm
Maximum height (4) .. .. .. 1120mm*
Minimum height (5) .. .. .. 720mm*
Maximum top traverse (2) .. .. 250mm
Overall width (6) .. .. .. 600mm
Sidebars (Denyer) .. .. .. 37.8 x 5.5mm
* 5mm less for Serial Numbers prefixed T2AA or T2AB
2.3 Movements
Maximum section loading is stated on each item and is
detailed below for reference:
Leg section .. .. 44kg
Head section .. .. 22kg
For accessories the maximum loading is stated on each
item and detailed in the User Handbook supplied with them.
For specific notes on the obese patient see the ‘Instructions
for Use’.
2.5 Electrical
2.5.1 Antistatic requirements
The table has an antistatic pathway from the table top,
through an internal resistor, to the castors.
CAUTION
To complete and maintain the antistatic
pathway the table must be used on an
electrically conductive or antistatic floor and
with mattresses supplied by Eschmann
Equipment.
2.5.2 Batteries
T able base:
Main batteries**:
Two, 12V 10.0Ah, sealed lead acid
Backup batteries**:
Two, 12V 1.2Ah, sealed lead acid
(see battery disposal caution in the ‘Instructions for Use’)
Infrared handset:
Two, 1.5V size AA Alkaline (Note: Must only be
changed in accordance with the notes in the section
6.6.19.2 to ensure the IP rating is not compromised).
The following table movements are maximums and cannot
be assumed to be available in all combinations of table
positioning (see Fig. 2.1 for illustration, the number in
brackets after the item details which part). For example,
with the table in its normal configuration and at minimum
height the maximum Trendelenburg and leg section
movements cannot be achieved due to the proximity of
the floor. Similarly with a large amount of tilt set, maximum
Trendelenburg cannot be achieved.
Max. Trendelenburg (1) .. .. .. 35°
Max. reverse Trendelenburg (1) .. .. 35°
Max. extension (4) .. .. .. .. 230°
Max. flexion (4) .. .. .. .. .. 90°
Head section (5) .. .. .. .. ±45°
Leg section (3) .. .. .. .. -100° +55°
Max. lateral tilt (7) .. .. .. .. ±18°
2.5.3 Internal battery charger**
Input
100-240V a.c. 2.4A (max) 50-60Hz
Output
29.2V d.c. 2A (max.) when charge state LED
red or orange, 27.6V d.c. when charge state
LED green
2.5.4 Fuses
2.5.4.1
Mains input fuses (item 17, Fig. 1.0)
Battery fuses (item 8, Fig. 1.0)
External fuses
2 x T4A (5 x 20mm) 250V
2 x T20A (6.35 x 32mm) 500V
P8/54 T-SM47j
T20-a
OPERATION TABLE
Note: The right hand fuse is linked to the main batteries
and the left hand fuse (i.e. nearest to the backup battery
switch) is linked to the backup batteries.
Mains plug fuse
.. .. 10A (type is dependent on plug
which may have been changed from that originally
supplied)
2.5.4.2
Battery fuses** (joining each battery pair)
Internal fuses**
2 x 30A blade type* (1 per battery pair)
(only accessible by engineer)
2.5.5 Duty cycle
This symbol is used to indicate the table’s duty cycle
which, in the worst case, is ‘60s : 600s’, the ratio of the
operating time to the sum of the operating time and the
ensuing interval (see note below). Each motor drive has
its own duty cycle and this is dependent on loading and
table position as detailed below.
Trendelenburg 1 : 4 (60s : 240s) at a maximum torque of
417Nm (e.g. 135kg load offset 31cm from the
fulcrum, or a 300kg load offset 14cm from the
fulcrum. Where this load is the patient and
accessories weight and the offset is how far the loads
centre of gravity is, from the centre of the column).
Traverse 1 : 4 (60s : 240s) when the table is
horizontal and at the maximum load of 300kg, or at
17.5° with a patient weight of 225kg, or at 35° with a
patient weight of 150kg.
Break 1 : 10 (60s : 600s) at maximum patient
weight of 300kg.
Height 1 : 4 (60s : 240s) at maximum patient
weight of 300kg (not offset).
Tilt 1 : 4 (60s : 240s) at maximum patient
weight of 300kg.
Note: The duty cycles above are all for the worst case (i.e.
maximum loads). For reduced loading the above duty
cycles can be increased.
2.7 Use in conjunction with other
equipment
2.7.1 Electrosurgical equipment (h.f.)
The T20-a operation table has been designed to minimise
the possibility of accidental electrosurgery burns and can
be used in conjunction with electrosurgical equipment.
However, contact with any metal surfaces (e.g. table side
bars, or other equipment etc.) can cause burns during
electrosurgery and must be avoided.
2.7.2 Defibrillation equipment
With the mains cord attached the equipment has
defibrillator proof applied parts with type BF protection
against electric shock.
2.7.3 Other
When the T20-a is used in conjunction with other infrared
controlled devices, their controllers should be checked to
ensure that no interference between them and the T20-a is
possible, prior to surgical intervention. Also see the
‘Instructions for Use’.
2.8 Standards compliance
The table has been designed and built to comply with the
following international standards:
BS EN 60601-1: 1990 (issue 2, October 1997)
BS EN 60601-1-2: 1993
BS EN 60601-2-46: 1998
BS EN 60601-1-4: 1997
2.9 Environmental conditions
2.9.1 Operating environment
The table has been designed to operate in the following
environment:
Temperature range .. .. 10°C to +40°C
Pressure range .. .. .. 69KPa to 106KPa.
Humidity range .. .. .. 30% to 75% RH
non-condensing.
2.6 Classification and symbology
All the symbols used on this table are shown and explained
in the ‘Instructions for Use’. These detail the safety category
and class of this table as marked on the table or section by
the use of these symbols.
2.9.2 Transport & storage environment
The table can be transported and stored safely, in the
following environment:
Temperature range .. .. -30°C to +50°C
Pressure range .. .. .. 69KPa to 106KPa
Humidity range .. .. .. 30% to 90% RH
non-condensing.
** NOTE: Items marked ** are to be changed with caution. During change or
replacement they must only be disconnected for a maximum of 60 seconds. If
battery power is removed from the table for longer than this then reconditioning
of the battery management system must be carried out, see section 6.6.26.
T -SM47j P9/54
1
4
(see section 2.2)
2
5
(see section 2.2)
6
3
7
These are maximum movements for each aspect, they may not be available in certain combinations (e.g. maximum
tilt and maximum Trendelenburg). Movements that could cause damage cannot be catered for (e.g. position of the
leg section).
Fig. 2.1 Major dimensions and movements
P10/54 T -SM47j
T20-a
OPERATION TABLE
Fig. 2.2 Maximum patient weight v table position graphs
T -SM47j P11/54
Fig. 2.3 Maximum patient weight v table position graphs
P12/54 T -SM47j
T20-a
OPERATION TABLE
3.0 TECHNICAL DESCRIPTION
See Fig. 3.1 and Appendix 3 for schematic diagrams.
3.1 Power supply assembly
This assembly (Part number 111765) which is located in
the table base, has no user serviceable parts and must be
changed as a complete unit. The assembly includes, a
Battery charger loom, a Battery charger module, a Battery
management PCA, a Battery connector loom, a Chassis
plate, two Battery support brackets, a Switch, two Fuses
(32 x 6.35mm 20A ‘T’ type), two Fuse holders, two battery
pairs and all connections, cable ties and screws etc.
3.2 Control electronics
3.2.1 Overview
The control electronics for the T20-a is distributed between
two PCA ’s (the ‘4 actuator PCA ’ and the ‘3 actuator PCA ’).
These two PCA’s contain three distinct microprocessor
daughter PCAs (two on the ‘4 actuator PCA’ and one on
the ‘3 actuator PCA ’).
The ‘4 actuator PCA’ (111524) is located on the column
and includes the ‘main controller’ and the ‘4 actuator
controller’. Each of these ‘controllers’ consists of a
‘microprocessor daughter PCA ’ (1 11526) which have their
control electronics on the ‘4 actuator PCA ’.
The ‘Three actuator PCA’ (111525) is located in the long
trunk section of the table and contains the ‘3 actuator
controller’, another ‘microprocessor daughter PCA’
(1 1 1526) with its control electronics on the ‘Three actuator
PCA’.
3.2.1.1 Microprocessor daughter PCAs
The daughter PCAs consist of a Motorola MC68HC912B32
micro controller, a watchdog circuit, an RS232 line driver
and an SPI UART and RS485 line driver. All the micro
controllers on the T20-a require these components. The
RS232 communications can be used to provide a telemetry
link to custom software running on a PC. Once fitted to
their respective controller boards the micro controllers are
programmed with the appropriate software application.
There is a ‘main controller application’ (110442) and an
‘actuator controller application’ (110443). Both the 4actuator and 3-actuator are programmed with the same
‘actuator controller application’ (110443). A configuration
file is then downloaded to each micro controller that
specifies which controllers are present on which board. It
is possible to configure any actuator to any board, however
the configuration of the electronics is specific to each
actuator.
3.2.1.2 The ‘main controller’
The ‘main controller’ provides the control and supervisory
functions for the table. This consists of the interface to the
infrared handset, corded handset (via RS232), footswitch
and standby panel. It also controls the table power LED.
The main controller communicates with the two actuator
controllers (one of which is co-located on the 4 actuator
PCA) by means of an RS485 multi-drop bus. This system
enables multiple slave controllers to be attached at any
time. The main controller issues a health check poll
message to each of the actuators (up to four of which can
be controlled by the single PCA) to ensure that they are
functioning correctly .
When a command is received from any of the user-input
devices the main controller issues the appropriate
movement commands to the required actuator (or actuator
groups in the case of combined movements).
3.2.1.3 The ‘4 actuator PCA’
The ‘4 actuator PCA ’ is responsible for movement of four
actuators on or within the table’s column. These are the
‘top and bottom height actuators’ inside the column
assembly , the ‘Trendelenburg actuator’ and the ‘Tilt actuator’
mounted on the column. A number of signals control the
movement of each actuator.
A PWM signal is used to set the speed of the motor; digital
signals control direction (forward/reverse), a digital signal
enables the drive circuit and another digital signal effects
a brake on the motor by shorting the windings together.
The electronics provide a digital fault signal to indicate when
there is a problem with the control circuit, or an over current
situation has occurred. An analogue signal is also provided
on all but the ‘bottom height actuator’. The analogue signal
on the top height actuator is the output from a potentiometer
that indicates the combined position of the height actuators.
Although the column contains two motors, there is only a
single potentiometer to indicate the height of the column.
This analogue signal is fed to the ‘top height actuator’; the’
bottom height actuator’ is effectively slaved to the top.
3.2.1.4 The ‘Three actuator PCA’
The ‘Three actuator PCA ’ is responsible for movement of
the three actuators within the tables long and short trunk
sections. These are the ‘left break actuator’, ‘right break
actuator’ and the ‘traverse actuator’. These actuators are
controlled by the same signals as on the ‘4 actuator PCA ’.
In terms of feedback, both the ‘left and right break actuators’
have potentiometers and the ‘traverse actuator’ has limit
switches which open when the long trunk reaches either
end of its movement. The ‘left and right break actuators’
are independently controlled to move at a set speed and
to maintain a minimum deviation between them.
T -SM47j P13/54
3.2.2 Handset overview
There are two versions of handset, a cordless type (infrared
handset) with an infrared emitter powered by 2 AA cells
and a corded version (corded handset) with an RS232 link
to the main processor on the ‘4 actuator PCA’. The latter
version derives its power from the T20-a.
3.2.2.1 Infrared handset
The 4 x 5 matrix keyboard is decoded using a proprietary
keyboard decoder. This device is powered down and
remains dormant until a key is pressed causing its clock
oscillator to be initialised. The key is decoded and the 38kHz
modulated signal is fed to the infrared LED via a FET . The
whole system is powered via 2 AA batteries
3.2.2.2 Corded handset
The 4 x 5 matrix keyboard is decoded using a proprietary
keyboard decoder. This device is powered down and
remains dormant until a key is pressed causing its clock
oscillator to be initialised. The key is decoded and the 38kHz
modulated signal is fed to a PIC processor. The processor
decodes the output from the keyboard decoder into RS232.
This output is fed to an RS232 line driver. The corded
handset’s power is supplied directly from the T20-a, 5V
power supply . The handset contains a DC-DC converter to
supply 3.3V for the keyboard decoder. There are indicator
LED’s to show the charge status of the table batteries (main
and standby).
P14/54 T -SM47j
T20-a
OPERATION TABLE
PROCESSOR
CONTROL
CONTROL FROM
HOST MICRO
FET DRIVERS
POSITIONAL
FEEDBACK
OVER
CURRENT
MANAGER
MOTOR
Basic control and feedback - all actuator drivers
AXIS TILT
AXIS TREND
AXIS HEIGHT 1
AXIS HEIGHT 2
POSITION ENCODERS AND
ANCILLARIES
OVER CURRENT MANAGERS
PROCESSOR COMMUNICATIONS
44
CONNECTOR 64 WAY
INTERFACE
12
4
Processor PCA
BatteryKeyboard
Power Management
Keyboard Encoder
POWER
MANAGEMENT
AXIS BREAK RIGHT
AXIS BREAK RIGHT
AXIS TRAVERSE
POWER
MANAGEMENT
CONNECTORS
INC:
CONNECTORS & INTERFACES
MICRO CONNECTORS
Four Actuator PCA
CONNECTORS
POSITION
MONITORS
OVER CURRENT
MANAGERS
Infrared Driver / Emitter
Handset remote version
Connector/LeadKeyboard
Power Management
Keyboard Encoder
Processor
RS232 Decoder/Driver
Three actuator PCA
Handset corded version
Fig. 3.1 Schematic diagrams
T -SM47j P15/54
4.0 SAFETY WARNINGS
4.1 ‘Service position’
When the four M10 screws (each side) that secure the
trunk sections to the pedestal are removed, to place the
table in the ‘Service position’ as detailed in section 1.9,
always take extreme care (and ensure table is switched
‘off’ before tilting top into or out off the ‘Service position’).
When the M10 screws are removed the table trunk sections
may tilt dramatically unless the sections are fully supported
during screw removal. Always lower the trunk sections into
(and out of) the ‘Service position’ slowly and always return
the table trunk sections to the ‘normal’ position (taking care
not to trap fingers) as soon as possible, replacing the eight
M10 screws securely. Also remove the following before
placing the table into the ‘Service position’:
Head section Leg section
Trunk mattress All accessories
When powering the table in the ‘Service position’ using
tool T2203 (to connect the table top connector blocks)
extreme care should be taken and powering the table in
this position should be limited to essential testing only . It is
preferable to return the table out of the ‘Service position’
before powering the table.
4.2 Lifting
During some of the procedures detailed in this manual it is
necessary to lift heavy assemblies. These are the long and
short trunk assembly, the wrapround assembly and the
telescopic assembly. These all require two people to lift
safely and any procedure that requires these to be removed
from the table should not be attempted if two people are
not available. Other components although not heavy
enough to require two people, should be handled using
the correct lifting techniques to minimise personnel injury .
It is advised that suitable protective footwear is worn when
handling heavy parts.
4.3 M10 trunk screw removal
When removing the four M10 (hexagonal head) screws
that secure the trunk sections to the column, always ensure
that precautions similar to those detailed in 4.1 above are
taken. Remove all accessories, sections and trunk mattress
and support the trunk sections during screw removal.
4.4 Trend and tilt actuator removal
When the Trend and /or tilt actuators are removed the trunk
sections will not be stable. Before removal follow similar
precautions to those detailed in section 4.1. Remove all
accessories, sections and trunk mattress and support the
trunk sections during actuator removal. Replace the
actuator as soon as possible.
4.5 Working with mains voltage
The only time that it may be required to work with mains
voltage applied to the table is whilst testing the battery
charger. During this procedure ensure that normal safe
working procedures are employed for an activity that entails
working with mains voltage, such as:
i Reduce the amount of live work to the minimum
possible.
ii Use common sense and stop working if
approached, distractions can kill.
iii Ensure the area is clear of all unnecessary
personnel or warn people in the area to stay
clear during live work. Also ensure that you are
not entirely alone and that someone could come
to your assistance if you should suffer an electric
shock.
iv Only use the correct equipment, probes and
cables for the work in hand.
v Mains power should be supplied via an RCD
(residual current device).
vi Turn of f the mains power whenever possible to
reduce risks.
4.6 Gas springs
When removing or servicing the table head and leg sections
gas springs refer to the warning in section 6.5.1.2. They
do not require lubrication and do not attempt to open them.
Also note the disposal notes provided in 6.5.1.2 (vii).
4.7 Hot parts on PCAs
During service and when covers are removed note that
parts of the PCAs can become hot enough to cause burns.
Beware that touching these assemblies when hot could
result in unexpected body movements.
4.8 Biological contamination
During servicing of the table it is advised that protective
gloves should be warn to avoid biological contamination. It
is preferable that the table be cleaned and disinfected
before service.
4.9 Connection of leads
When connecting test leads to the table during service
ensure that these do not constitute a tripping hazard.
4.10 Leaking batteries
In the unlikely event of a battery leaking in the table base
avoid spreading the contamination (sulphuric acid) and:
i Wear suitable personnel protection (goggles, gloves
etc.) do not smoke and avoid sparks.
ii Use a bonding agent such as sand, or sodium
carbonate to absorb and neutralise the bulk of the
electrolyte. Wash (and rinse well) the contaminated
area with water, taking care not to splash electronics
or any other table base components.
iii Do not flush electrolyte into the sewer system but
dispose of the used bonding agent and all cleaning
materials in accordance with local waste regulations.
In the case of skin contact wash and rinse immediately
with water. If splashed into eyes rinse well with water and
seek medical advice. If acid mist is inhaled, inhale fresh
air and seek medical advice.
P16/54 T -SM47j
T20-a
OPERATION TABLE
5.0 MAINTENANCE
5.1 Power supply assembly
This assembly (Part number 111765) which is located in
the table base, has no user serviceable parts and must be
changed as a complete unit (also see section 3.1).
5.2 T able fault finding
5.2.1 The ‘Instructions for use’ contains a basic fault finding
table that can be used to solve any minor problems. This
covers the main user errors (i.e. there is no fault) that can
occur when the user has not read and understood the
‘Instructions for use’. It also contains the first line of fault
finding (i.e. check external fuses, try another handset, try
another mains lead). The following section (5.2.2) provides
a test sequence to help determine the fault (for the majority
of faults that may occur) that could stop the table responding
to an input via a control device. Mechanical faults are
normally self evident in that a part is worn, damaged or
broken. In this case refer to the appropriate section of this
manual for part replacement information. Appendix 3
provides the schematic diagrammes that can also be used
in fault finding.
5.2.2 Follow the sequence below to identify most major
faults that result in a lack of response to a control command:
1 When the table is initially switched ‘on’ is the table
‘on’ LED (item 23 of Fig. 1.0) bright, dull or ‘off’ for
the first few seconds.
If dull turn the table ‘off’ wait at least 10 seconds
and then turn back on. If the LED is still dull or
‘off’ this indicates an electronics fault see 5.2.3.
If bright move to 2 below.
If it is flashing this also indicates an electronics
fault see 5.2.3.
2 Try the ‘standby control panel’ (any motion except
Trendelenburg), if this fails try the ‘standby control
panel’ with the backup battery switch depressed.
If the table works from the ‘standby control panel’
this indicates a fault with the control device or
its connection to the table.
If the table works from the ‘standby control panel’
only when the backup battery switch is pressed
this indicates a fault with the main batteries
(replace the whole Power supply unit).
Now try Trendelenburg from the ‘standby control
panel’, if this and only this motion works it indicates
a problem with the main control PCA.
3 If one of the motor groups ‘only’ has failed then this
indicates a problem with its associated PCA as follows:
Break and traverse - Three actuator PCA
Tilt, T rend and Height - 4 Actuator PCA
This distinction may help in reducing the amount of
diagnostics and cover removal.
4 Remove covers and check battery fuses (see
section 5.3.1 and 6.6.26). Also look to see if the
PCA indicator lights are flashing ‘on’ for 1 second
and ‘off’ for 1 second. If they are ‘off’ or flashing
faster, this indicates an electronics fault see 5.2.3.
5 If the fault is only apparent for one motion this could
indicate a failed motor or failed sensor for that motion,
or, an electronics fault. If the motion starts and then
stops immediately this could indicate a failed sensor
or an over current situation. Test motor (as detailed
in section 6.6), if the motor works and no small
movement is observed following a demand for that
motion, it indicates an electronics fault, see 5.2.3.
5.2.3 Electronic faults can only be determined with the
table connected to a PC with the ‘T20 Application Software’
installed. Consult the Application Software Manual (as
detailed in section 1.1) which provides guidance on fault
diagnosis. Also note that when correcting electronic faults
(and following some parts replacement) the table will require
reprogramming, reconfiguring or recalibration. These aspects
are also fully covered in the Application Software Manual.
5.2.4 Break motion control
5.2.4.1 The two break arms are independently controlled
and are synchronised to operate within a programmed limit
of each other. This control system can result in small
variances that appear as a slight misalignment, this is
acceptable and a part of the normal table control software
routine. In the unlikely event that this deviation goes outside
of the programmed limit the table break motion (only) will
stop working. This can sometimes be corrected as below .
5.2.4.2 Whilst observing the two break arms press (for
approximately 0.5 seconds only) a break control button on
the handset (B7 or B8 of Fig. 6.9) once or twice. If this
makes the deviation worse press the other break control
button as above once or twice. If the break motion still
does not work correctly after this there could be a fault in
one of the following:
Break motor
Break potentiometer
Wiring to any of the above
Significant uneven table loading*
*This problem will only be evident during use and if
investigated at service it will be difficult to reproduce.
5.2.5 Trunk section connector blocks
5.2.5.1 If all the top table functions stop working (e.g. break
and traverse) the connector blocks (item 5, Fig. 6.7 and item
14, Fig 6.3) could be failing to connect correctly due to
contamination etc. Check that a good contact is being made
between the column and trunks connector blocks.
5.3 Fuse location
5.3.1 All fuse locations are identified in section 2.5.4 and
Fig. 1.0. DO NOT REMOVE OR CHANGE INLINE BA TTERY
FUSES UNLESS YOU HA VE READ SECTION 6.6.26.
T -SM47j P17/54
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