Dantherm MTS4 User manual

DA
Betjeningsvejledning DVC-styring
Side 3
EN
User’s guide for the DVC controller
Page 23
DE
FR
MTS4 Outdoor Enclosure
Service manual
EN
Dantherm No. 045893 • rev. 2.3 • 16.03.2012
Motorola No. 6866588D43

Der tages forbehold for trykfejl og ændringer
Dantherm can accept no responsibility for possible errors and changes
Irrtümer und Änderungen vorbehalten
Dantherm n’assume aucune responsabilité pour erreurs et modifications éventuelles

3
045893 •Version 2.3 • 16.03.2012
1. Introduction
Overview
Product coverage
This manual covers the MTS4-outdoor enclosure with all options including power back-
up supplied by batteries (product no. 352894) The MTS4-outdoor enclosure is based
on the Dantherm ICS 2000 platform.
Should you have required the Fuel Cell power backup solution with the MTS4-outdoor
enclosure (product no. 352895), the fuel cell and hydrogen handling and storage is not
covered in this manual, but is described in the IPSM-A1600 power backup module for
installation in the MTS4-outdoor enclosure manual (product no. 046234), 6866600D34,
which is a supplement to this manual (product no. 045893 –Motorola product no.
6866588D43).
WARNING
It is the responsibility of the operator to read and understand this service manual
and other information provided, and to use the correct operating procedures.
Read the entire manual before the initial start-up of the installation of the MTS4-outdoor
enclosure. It is important to know the correct operating procedures for the unit and all
safety precautions to prevent the possibility of property damage and/or personal injury.
Safety
The MTS4-outdoor enclosure including the IPSM-A1600 power backup system should
be protected against traffic accidents by a fence or a concrete barrier and obey all other
legal requirements for installation and storage of hydrogen high pressure bottles which
are not listed in this manual.
Ventilation re-
quirement
In case the MTS4-outdoor enclosure is placed indoor in
a closed room, the ventilation capability of the room
should minimum be in accordance with the battery
standard and battery manufactures recommendations.
This can be found on a label situated next to the batter-
ies (when installed).
The requirement is 0.19 m3/h.
When the cabinet is installed outdoor, no additional
ventilation is required with required degassing kit in-
stalled (tube system from battery valve to exterior)
through retaining grommet. Always check if this tube
has not been damaged or removed.
Left bay of the enclosure above the power distribution panel offers a 19” rack system
with 12RU available for auxiliary equipment.
It is important that any active component in the rack, including those components that
will be installed later in addition to Dantherm’s deliverable, must have a self-protecting
mechanism, which switches off the component in case of an overheat situation.
Further it is important that the heat dissipation of equipment installed do not exceed
200 W or max. permitted ambient temperature will have to be de-rated.
Continued overleaf

4
1.1 General information, continued
Table of contents
This installation manual covers the following main topics:
Topic
See page
1.1 General information
6
2. Product and functional description
8
2.1 MTS4-outdoor enclosure
9
2.2 Optional equipment
11
2.3 Power distribution panel
13
2.4 Heat exchanger –MHX 85
17
2.5 Door stop
20
3. Get ready for use
21
3.1 How to unpack and mount the MTS4-outdoor enclosure
22
3.2 How to install power to the MTS 4-outdoor enclosure
26
3.3 How to install the battery pack (backup power)
30
3.4 How to install the MTS4 into the outdoor enclosure
34
3.5 How to power up the MTS4-outdoor enclosure (cold start)
38
4. Service guide
41
4.1 Preventive maintenance
42
4.2 Spare parts
44
4.3 Fault finding
56
4.4 Service agreement
57
5. Technical information
58
5.1 Technical data, MTS4-outdoor enclosure
59
5.2 Technical data, MHX 85 heat exchanger
61
5.3 Wiring diagram, MHX 85 heat exchanger
64
5.4 Wiring diagrams MTS4-outdoor enclosure –power
distribution panel
65
5.5 References for the wiring diagrams
73
Appendix A - Mounting template
75
Appendix B - MTS4-outdoor enclosure check list
76
Continued overleaf

5
045893 •Version 2.3 • 16.03.2012
1.1 General information, continued
Revisions
This is the revision history of this manual:
Date
Section
Change
11/2-10
20/5-10
16/3-12
1
2.3
2.3
2.3
2.4
4.2
4.2
4.2
4.2
4.2
4.2
4.2
4.2
4.2
4.2
4.2
4.2
4.2
4.2
4.2
4.2
4.2
5.4
2
2.1
2.1
2.3
5.5
5.5
2.3
3.5
4.2
Changed number
Changed alarm names, new column 4 and 1st row added
Alarm pin layout changed
Operation of Generator switch, added
Control system, “max.” added
Dantherm part 046392, description changed/added
Dantherm part 046398, description changed/added, new illustr.
Dantherm part 046400, description changed/added
Dantherm part 046496, description changed/added
Dantherm part 060575, description changed/added
Dantherm part 062905, added
Dantherm part 064624, added
Dantherm part 064627, added
Dantherm part 064628, added
Dantherm part 064629, added
Dantherm part 064630, added
Dantherm part 064631, added
Dantherm part 064632, added
Dantherm part 064633, added
Dantherm part 064634, added
Dantherm part 064635, added
Dantherm part 064636, added
Wiring diagrams changed, and new added
Illustration changed
Illustration changed
New text in line 1 on page 10
Minor text changes page 15
Minor text changes page 72
Wire colors added
Illustrations with generator switch updated
Illustrations with generator switch updated
Illustrations with generator switch updated. Added new supply
switch kit.

6
1.1 General information
Introduction
This section gives the general information about this service manual and about the
MTS4-outdoor enclosure.
Manual,
part number
Part number of this service manual is 045893.
For Fuel Cell power backup option: please see the manual IPSM-A1600 power backup
module for installation in the MTS4-outdoor enclosure (product no. 046234).
Target group
The target group for this service manual is the technicians who install, maintain, and
exchange parts on the unit.
Copyright
Copying of this service manual, or part of it, is forbidden without prior written permis-
sion from Dantherm Air Handling A/S.
Reservations
Dantherm Air Handling A/S reserves the right to make changes and improvements to
the product and the service manual at any time without prior notice or obligation.
MTS4-outdoor en-
closure
Dantherm Air Handling A/S, Marienlystvej 65, DK-7800 Skive hereby declare that the
product mentioned below:
Product No.: 352894 MTS4 outdoor enclosure basis
and the 2 versions below with enclosure extensions for storage
352895 MTS4 outdoor FC-5
352896 MTS4 outdoor FC-3
are in conformity with the following directives covering the provisions of the normative
European Council Directives:
2006/42/EC Directive on the safety of machines
2006/95/EC Low Voltage Directive
2004/108/EC EMC Directive
Description: MTS4 outdoor enclosure is a 2 door steel based outdoor enclosure
equipped for accommodating and servicing an MTS4 radio base station. The enclosure
has multiple configurations ranging from a standard configuration with only a basic set-
up up to a full integrated option list as defined in the service manual no 045893. Basis
is equipped with a door mounted heat exchanger (CE marked), a power distribution
panel (CE-marked) and internal cables, cabin lights, a backup installation (battery pack
using VRLA size batteries (optional)), battery charger, surge arrestors etc. Items not
listed in the service manual are not covered by this declaration.
The versions 352895 and 352896 with enclosure extensions for storage also offers a
power backup system (IPSM-A1600) based on fuel cell technology using hydrogen as
energy source. This backup system is CE-marked and further described in manual p/n
046614.
and Manufactured in conformity with the following harmonised standard:
EN60529:2001 IP55 (Degree of protection provided by enclosures)
EN 12000-1:2005 Safety of machinery –Part 1: Basic terminology
EN 12000-2:2005 Safety of machinery –Part 2: Technical principles
EN 60 950-1:2006 Installation safety (CB by Intertek, ref: 714719-01)
EN 60 950-22:2006Information technology equipment - Safety - Part 22:
Equipment installed outdoors
EN50272-2:2001 Battery installation
Continued overleaf

7
045893 •Version 2.3 • 16.03.2012
1.1 General information, continued
MTS4-outdoor en-
closure
, continued
EN 61 000-2:2005 Immunity
EN 61 000-3:2007
+A11:2004 Emission (EN 55022 version:
1998+A1:200+A2:2003_Class B)
ETSI EN 300 019-2-1 v2.1.4
Storage: not temperature controlled storage locations:
T 1.2
ETSI EN 300 019-2-2 v2.1.2
Transportation: public transportation. T2.3
ETSI EN 300 019-2-4 v2.2.2
In use: non-weather protected locations T 4.1 (or T4.1E)
ETSI ETS 300 753 october 1997
Acoustic noise
It is further declared that the installation and commissioning of MTS4 base station and
site installation are not covered by to this declaration.
Skive, 11.06.2008
Recycling
The MTS4-outdoor enclosure is designed to last for many years. When the time
comes for the unit to be recycled, the unit should be recycled according to national
rules and procedures to protect the environment.

8
2. Product and functional description
Overview
Introduction
This section will give you a product and functional description of the MTS4-outdoor en-
closure.
A detailed description of the MTS4-outdoor enclosure is to be found on the following
pages.
Illustration
This illustrates the MTS4-outdoor enclosure with the MHX 85 (heat exchanger unit)
hanging on the right door:
Content
This section covers the following topics:
Topic
See page
2.1 MTS4-outdoor enclosure
9
2.2 Optional equipment
11
2.3 Power distribution panel
13
2.4 Heat exchanger –MHX 85
17
2.5 Door stop
20

9
045893 •Version 2.3 • 16.03.2012
2.1 MTS4-outdoor enclosure
Introduction
This section will give you a description of the MTS4-outdoor enclosure and its function-
ality.
The MTS4-outdoor enclosure is designed to accommodate a Motorola MTS4 base sta-
tion, which is further described by Motorola, part number 6802800U74 “MTS2 and
MTS4 configuration, installation and service manual”. For more information please con-
tact Motorola.
The MTS4-outdoor enclosure is designed to withstand rough environment and many
years of service. Basis is a welded steel frame with dismountable side panels with pro-
tected double gaskets for protecting the sealed environment inside.
Illustration
This illustrates where the basic parts are installed in the MTS4-outdoor enclosure:
Continued overleaf

10
2.1 MTS4-outdoor enclosure, continued
Parts
This table gives information about the basic parts installed in the MTS4-outdoor enclo-
sure:
Part
1
Plinth with removable painted cover panels including front access to generator
cable
2
Drain system
3
Shelf for storing battery pack
4
Basic cable routing for specified equipment
5
Double 19” rack system in left bay
6
Door stop system
7
Internal insulation panels
8
Dismountable painted protection roof
9
RF protection cover
10
Heat Exchanger mounted on right door
11
Cabinet with 2 doors with 3 position swing lock system with stainless steel
swing handle with key system
12
Air divider plate for MTS4
13
Mounting system for MTS4
14
Cable glands in bottom plate
15
Power distribution panel with protection cover

11
045893 •Version 2.3 • 16.03.2012
2.2 Optional equipment
Introduction
The MTS4-outdoor enclosure might be equipped with different options, shown in the
following list.
The chosen options are installed from factory but afterwards they can be ordered as
spare part kits. Installation and service instructions for the spare parts will be a part of
the spare part kits.
NB: The Motorola option numbers in the option list below can not be used when order-
ing spare parts. The spare parts have separate Motorola spare part numbers.
Please note that 48VDC power supply is required for heat exchanger to operate. A bat-
tery pack is required for MTS4 PSU to be able to power the heat exchanger.
Part
Function
Dantherm
No.
Motorola
No.
Heater
In case of cold external temperatures the
heater supplies heat maintaining required
minimum temperatures for the batteries as
well as maintaining a non condensing envi-
ronment when the MTS4 is not in opera-
tion. (DBK Cirrus 80 with thermostat)
046123
TG00116AA
Smoke de-
tector
Detects smoke and sends an alarm signal
to the MTS4 controller (Regin S65)
046122
TG00117AA
Cabin Light
LED panel light (48VDC) installed in both
sides activated by door contacts
046132
TG00119AA
GPS Surge
arrestor
Protection of the GPS equipment against
lightening or excess voltage. Can accom-
modate up to 2 S.A. (Polyphaser
DGX+6NFNF-A + jumper cable)
039911
TG00111AA
Antenna
Surge arre-
stor
Protection of the receiver against lighten-
ing or excess voltage. Can accommodate
up to 5 of S.A.s. (Polyphaser VHF50HD +
650 mm cable)
045884
TG00112AA
Microlink
Surge arre-
stors
Protection of Microlink equipment when in-
stalled. Can accommodate up to 6 of S.A.
(Pholyphaser GT-NFF-AL)
045887
TG00150AA
External bat-
tery charger
Quick charger for the batteries.
1600 W Power One Aspiro charger of-
fered. Incl. shelf for support during
transport. Battery temperature sensor in-
stalled
045892
TG00115AB
Powermeter
Shows AC power consumption (ABB 3
phase ODIN)
046164
TG00114AB
Generator
switch
Switch for easy selection between power
sources, incl wiring and external plug for
generator
NB: Generator switch and power meter
can not be present at the same time
046140
TG00154AA
Continued overleaf

12
2.2 Optional equipment, continued
Part
Function
Dantherm
No.
Motorola
No.
Backup sys-
tem, battery
powered
Supplies backup time when power is una-
vailable.
2 shelves for 2 sets of batteries. Each set
can give 155Ah.
Only lower shelf is safe for transpor-
tation when installed.
(Enersys 12V155FSx4 pack incl. degas-
sing kit + internal wiring) and (LVD if re-
quired) For longer backup time, fuel cell
system is available
046137
TG00108AB
LVD relay
Low Voltage disconnect relay. This relay is
placed in line with the battery cable and
enables a battery disconnect function con-
trolled by the MTS4 when battery is dis-
charged below recommended voltage
(40,5VDC).
046118
TG00151AA
Data line
Surge arres-
tor
Protection of the data line against lighten-
ing or excess voltage (Polyphaser NX2-05
with shielded cat 5)
039886
TG00118AA

13
045893 •Version 2.3 • 16.03.2012
2.3 Power distribution panel
Introduction
This section will give you a description of the power distribution panel (PDP) and its
functionality.
The power distribution panel (PDP) is located in the mid section in the left bay of the
MTS4-outdoor enclosure.
Illustration
This illustration gives an overview of the power distribution panel which is build into the
MTS4-outdoor enclosure
Please see section “5.5 References for the wiring diagrams”, page 73 for further refer-
ences of the power distribution panel.
Description
The power distribution panel (PDP) is the electrical centre of the MTS4 outdoor installa-
tion. It connects and distributes power to all functions inside the enclosure.
Various circuit breakers rated to protect the consumer and further surge protection
(overvoltage and lightning) as well as a RCCB (Residual Current Circuit Breaker) relay
are used to protect for potential earth faults. In Scandinavia also known as HPFI relay.
Optional a power meter can be included.
Various alarms for i.e open doors, high temperature, smoke etc. is also connected and
collected from the PDP.
The circuit breakers can also be used to activate or deactivate the function listed on the
overlay.
The basic PDP design is for installation into a19” rack system and offers a 2 row DIN
rail space each sized for 25 module and it is tested to fulfil the safety regulations in ac-
cordance to EN60950. It also has a CE marking.
Continued overleaf

14
2.3 Power distribution panel, continued
Power distribution
panel ON
Layout wise the PDP is split in 2 main sections.
230VAC is marked yellow and 48VDC is marked
green (see illustration on the previous page)
The illustration to the right shows the power entry
on the upper right section.
With the circuit breaker F1.7 and earth fault protec-
tion (HPFI F1.21) flipped upwards the PDP is ON
when power is connected to the enclosure.
Test and check
It is recommended that the small white test button on the HPFI is activated regularly
(every 6 month) to test function. Make sure Backup is active when doing this to avoid
any unplanned downtime on the Radio base station.
If a lightning or other surge voltage have hit the PDP the R1.13 transient protection
might have been damaged (and possibly saved the equipment inside). Check if the
easy replaceable blocks are okay by seeing if the window is still green.
AC area
All 230 VAC loads are connected to the 6 circuit
breakers on the left side of the PDP.
DC area
All 48VDC loads (40-60VDC) are connected to the
5 circuit breakers in the lower right corner of the
PDP + additional 2 small fuses for the cabin light
The one to the right switches off all 48 VDC distri-
bution inside the enclosure, except cabin light.
Flip open the F3.32 and F3.34 to disconnect cabin
light.
Option
In the middle of the upper row there is an optional
P1.29 space (covered with a blind if no options se-
lected).
Two options are currently considered.
This can be used for a multiple single phased pow-
er meter or a switch for dual power intake (genera-
tor switch). The illustration is showing the generator
switch installed. In shown position the mains power
is switched on.
Continued overleaf

15
045893 •Version 2.3 • 16.03.2012
2.3 Power distribution panel, continued
Alarm block
Behind the blind in the centre of the lower row there is an alarm block with screw termi-
nals which is connected to the alarm port (25pin D-sub on top of the MTS4).
All alarms that are to be collected here should be attached to the alarm block X4.2.
Alarm name
MTS4
D-25 pin #
Alarm
block #
Remarks
-
N.A.
N.A.
Door alarm –connectet to the MTS4
door connector (logically A-1 in the
basestation)
Heat exchanger-
warning
1
A-2
-
Spare
14
A-3
-
Heat exchanger -
alarm
2
A-4
-
Aux door alarm
15
A-5
Spare –free to use for other door(s)
Smoke detector
3
A-6
-
Inverter - alarm
16
A-7
Spare –used if inverter installed
Spare A-8
4
A-8
Spare –used if flooding sensor in-
stalled
FC malfunction
17
A-9
Defined in 1266510N38
FC no H2 or warn-
ing
5
A-10
Defined in 1266510N38
FC H2 STRING 1
is emty
18
A-11
Defined in 1266510N38
FC H2 STRING 2
is emty
6
A-12
Defined in 1266510N38
Spare A-13
19
A-13
Spare –used if low temp.sensor in-
stalled
Spare A-14
7
A-14
Spare –used if high temp.sensor in-
stalled
Spare A-15
20
A-15
-
FC Test signal
Supply
8
A-16
Defined in 1266510N38
FC Test
24
Relay out 1
Defined in 1266510N38
FC Test
12
Relay out 1
-
Spare output 2
25
Relay out 2
Ground (GND inputs)
Spare output 2
13
Relay out 2
-
Ground (GND in-
puts)
9, 10, 11,
21, 22, 23
GND in-
puts
-
Continued overleaf

16
2.3 Power distribution panel, continued
Alarm pin layout
Warning
The cover panel is easily removed by removing
the 4 screws holding it, but be aware of danger
when the cover is removed from the PDP.
Only Authorized personal should remove
the cover and do modification to the PDP.
Dantherm will not take responsibility to any
unauthorized modifications done to the PDP.
The PDP operates with a multiple single
phase system, which means 415VAC live
voltage can be found between live phases.
Operation of Gen-
erator switch (op-
tional)
The generator switch has 3 positions:
1: When turned to the left it selects the
power source connected to left set of
contacts (I) which will be the alternative
power source, normally a diesel genera-
tor connected to the CEEE connector lo-
cated in the plinth of the cabinet.
0: This position (mid picture) will disconnect
External power sources.
2: selector turned right (lower picture).
This is the normal position with mains on.

17
045893 •Version 2.3 • 16.03.2012
2.4 Heat exchanger –MHX 85
Introduction
This section will give you a description of the MHX 85 and its functionality.
The MHX85 is a high end heat-exchanger especially designed to meet the require-
ments and challenges within telecom applications.
Core of the product is the new revolutionary Dantherm plastic counter flow heat ex-
changer core, which offers unique performances. It is powered by top quality DC fans
and controlled by specially designed embedded microprocessor operated controller.
Sheet metal
The cabinet is made of aluzink®sheet metal parts. The heat exchanger outer cabinet
(chassis body) is made out of one big part sealed and riveted together in each corner.
One big lid is riveted to this part. Internal parts are riveted and screwed together. The
tightness between the inner- and outer circuit is obtained by use of soft foam/gaskets
and liquid sealant. Cleaning of the internal and external fans as well as cleaning of the
core is possible through inspection/service lids.
Mounting
The heat exchanger unit is designed to be fixed to the inside of the door by using 4
long M8 screws (13 mm hex head). A gasket is applied between heat-exchanger and
door duct to seal the airway and maintain the IP55 barrier.
Illustration
This illustration gives an overview of the
heat exchanger which is build into the
MTS4-outdoor enclosure (seen from inside
the cabinet):
Two separate air
flows
The two air flows (internal/external) are totally separated (IP55). The external air is only
used to cool down the internal air via the heat exchanger. The air flows are never
mixed.
Internal air flow
The warm internal air is sucked from the enclosure into the internal fan at the top of the
MHX 85 and let through the heat exchanger, where it is cooled down.
After the cooling in the heat exchanger, the air is let back into the enclosure.
External air flow
The cold external air is sucked into the external fan at the bottom of the MHX 85 and let
through the heat exchanger, where it is cooling down the internal air.
After having passed through the heat exchanger, the air is let back to the external envi-
ronment at the top of the unit.
Continued overleaf
Air inlet, this is where the warm air
returning from the enclosure is be-
ing sucked into the heat exchanger
to be cooled down
Supply air outlet, from
where the cooled air is
supplied back to the en-
closure

18
2.4 Heat exchanger –MHX 85, continued
Control system
The MHX 85 heat exchanger is controlled
via a controller that controls the speed of
the fans.
The key features of the controller are:
Onboard temperature sensor (NTC
type)
Microproccesor based control in ac-
cordance with preselected strategy
Minor and major alarm output
Polarity protection
Input voltage -40 V DC to -60 V DC
Power consumption max. 120 W
Part
Function
RS 232
To be used for factory testing or to get further information from
the controller
Alarm LED
Gives signal about alarms:
Flashing = minor alarm (high temperature)
Constant = major alarm (fan or sensor failure)
Both alarms can be monitored (potential free contact) on the
power/alarm plug.
Sub-D 9 pin, male
Power and alarm plug
Pin designation:
1 N/C
2 + 48 V DC
3 + 48 V DC
4 Minor alarm +
5 Major alarm +
6 0 V DC
7 0 V DC
8 Minor alarm ÷
9 Major alarm ÷
Control strategy
This shows the control strategy for the controller:
See the table on the next page for an explanation of the values.
Continued overleaf

19
045893 •Version 2.3 • 16.03.2012
2.4 Heat exchanger –MHX 85, continued
Values
This table shows the set points/control strategy for the MHX 85 heat exchanger.
All listed temperatures are return air temperatures (from the enclosure to the heat ex-
changer). Fan speeds are detected and controlled from speed signals from the fans.
Reduction
Designation
Value
IR1
Minimum internal fan speed
1100 RPM
IR2
Maximum internal fan speed
2100 RPM
IT-
Cut off temperature, internal fan
0 °C
IT0
Cut in temperature, internal fan
5 °C
IT1
Ramp up temperature set point, internal fan
40 °C
IT2
Maximum RPM temperature set point, internal fan
50 °C
ER1
Minimum external fan speed
1100 RPM
ER2
Maximum external fan speed
2000 RPM
ET-
Cut off temperature, external fan
25 °C
ET0
Cut in temperature, external fan
30 °C
ET1
Ramp up temperature set point, external fan
45 °C
ET2
Maximum RPM temperature set point, external fan
50 °C

20
2.5 Door stop
Introduction
This section will give you a description of the door stop mechanism installed in the
doors of the basic MTS4-outdoor enclosure and its functionality.
Function
Both left and right door is equipped with a door stop “hook”, which will stop the door at
an opening angle of approx. 110°. When it hits the stop end it will snap and keep the
door in this position until it is released. The release is done by simply lifting the hook
and closing the door.
If the door opening angle should be more than the 110° the door stop has a further re-
lease feature. In approx. half way open position, the door hook can be completely lifted
out of the guide it normally operates in. By doing so the doors can reach a full 180°
opening angle.
Left door
The illustration to the right is showing the wind hook
located near the upper edge of the left door being
released enabling a full 180° opening.
The door stop is re-inserted in the guide in the
same way as it was lifted out.
Always put the hook back in the guide after it
has been disconnected to avoid personal injury and
physical damage to the enclosure.
Right door
The illustration to the right is showing the wind hook
located near the upper edge of the right door being
released enabling a full 180° opening.
The door stop is re-inserted in the guide in the
same way as it was lifted out.
Always put the hook back in the guide after it
has been disconnected to avoid personal injury and
physical damage to the enclosure.
WARNING
Forcing the doors at 180° might damage both doors and hinges.
With door stop disconnected there might be a risk of personal injury, especially in high
wind conditions, if a heavy wind hits the door and force it either open or shut can cause
personal injury on a person being behind this.
Keep the door stops in position.
Test and check
It is recommended to test the “hook” function on every visit.
The door stop can be damaged by rough use and in a high wind situation this can be
dangerous.
Report or correct malfunction to service responsible.