U.S. patent application number 13/066655 was filed with the patent office on 2011-08-18 for connection box solar panel.
Invention is credited to Lothar Fuhrmeister, Stefan Joergens, Michael Richter.
Application Number | 20110198120 13/066655 |
Document ID | / |
Family ID | 41130999 |
Filed Date | 2011-08-18 |
United States Patent
Application |
20110198120 |
Kind Code |
A1 |
Richter; Michael ; et
al. |
August 18, 2011 |
Connection box solar panel
Abstract
A box for connecting an output conductor from a solar panel with
a feed cable has a base mountable on the solar panel and formed
with a first hole for the panel-output conductor and a second hole
for the feed cable, a removable cover fittable with the base in a
closed position and forming in the closed position with the base a
substantially closed compartment, and at least one component
mounted on the cover in the compartment. The component is something
that affects transmission of electricity from the solar panel into
an electrical network connected to the feed cable or that affects
the microclimate inside the connection box.
Inventors: |
Richter; Michael;
(Schalksmuehle, DE) ; Joergens; Stefan;
(Schalksmuehle, DE) ; Fuhrmeister; Lothar;
(Schalksmuehle, DE) |
Family ID: |
41130999 |
Appl. No.: |
13/066655 |
Filed: |
April 20, 2011 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
12434734 |
May 4, 2009 |
7960650 |
|
|
13066655 |
|
|
|
|
Current U.S.
Class: |
174/548 ;
174/520 |
Current CPC
Class: |
H01R 13/6641 20130101;
H01R 4/4809 20130101; H02G 3/086 20130101; H02S 40/345 20141201;
H01R 13/5202 20130101; Y02E 10/50 20130101; H01R 13/506 20130101;
H02S 40/34 20141201 |
Class at
Publication: |
174/548 ;
174/520 |
International
Class: |
H05K 5/00 20060101
H05K005/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 3, 2008 |
DE |
102008022049.3 |
Claims
1. A box for connecting an output conductor from a solar panel with
a feed cable, the box comprising: a base mountable on the solar
panel and formed with a first hole for the panel-output conductor
and a second hole for the feed cable; a removable cover fittable
with the base in a closed position and forming in the closed
position with the base a substantially closed compartment; and at
least one gas-exchange element mounted on the cover, wherein the
gas-exchange element allows air to move between the compartment and
an outer environment.
2.-12. (canceled)
13. The box according to claim 1, wherein the gas-exchange element
is a sintered-metal plug.
14. The box according to claim 1, wherein the gas exchange element
is supported in the removable cover and in contact with the outer
environment of the box through a groove configured in the
cover.
15. The box according to claim 1, wherein a channel leads to
openings at an edge of the removable cover.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a connection box. More
particularly this invention concerns a connection box for a solar
panel.
BACKGROUND OF THE INVENTION
[0002] A typical the connection box, in particular for solar
panels, comprises a cover that upwardly closes a base that is
itself attached to the back of a solar panel. The base has a first
opening for at least one output conductor or cable from the panel
and at least one opening for a feed cable exiting from the panel
and going to the network using the solar-generated electricity. The
base also has a compartment that holds circuit elements for
connecting the panel-output cable to the feed cable.
[0003] A the connection box of this type is disclosed, for example,
in 10 2005 008 123 A1. the base of the connection box here has a
strip-conductor structure that is provided with cable clamps. The
cable clamps function to connect the feed cables and the
panel-output cables to the strip-conductor structure.
[0004] In US 2005/0230140 screw-type terminals are provided to
which the panel-output cables and the feed cables are electrically
connected by strip-conductor structures.
[0005] U.S. Pat. No. 7,444,743 discloses a strip-conductor
structure inside a connection box in which the feed cables and
panel-output cables are connected by crimping to the
strip-conductor structure. For bridge diodes, the strip-conductor
structure forms forked-spring-contact-type contact clips.
[0006] DE 20 2005 018 884 describes a connection box whose opposite
side walls has holes through which panel-associated panel-output
cables and the feed cables are routed into the connection box.
Bridge-like clamping components are placed is between the cables to
be connected and are analogous to the strip-conductor structures.
At their ends, these clamping components have clamp springs to make
the contact of the cables and provided with contact openings in
which the bridge diodes can be inserted.
[0007] The above-described the connection boxes have various
circuit elements depending on the application they are put to, with
the result that a different the connection box essentially exists
for each application in terms of constructive design and size as
well as the mounting of circuit elements.
[0008] The circuit elements used within the scope of the invention
are defined as elements that have an effect on the transmission of
electricity from the solar panel into the electrical network, or
affect the microclimate exiting inside the connection box.
Explicitly not circuit elements are seals between the cover and the
base of the connection box. These do not have any effect on the
transmission of electricity and also have little effect on the
microclimate existing in the connection box. Instead, it is in fact
such seals that create a microclimate in the connection box.
[0009] Thus in the prior art there are two different possible
approaches for sealing the base, in particular, sealing the
compartment containing the circuit elements. In a first approach,
provision is made whereby after installation of the box on the
solar panel, and the panel-output cable and the feed cable, the
compartment is sealed with a resin. This enables the circuit
elements inside the compartment to be reliably protected against
moisture and contamination.
[0010] A second solution provides an annular seal between the cover
and the base of the connection box, the seal similarly forming a
compartment inside the connection box that is protected against
contamination and moisture.
[0011] A change in the connection equipment on the part of the
manufacturer of the solar panel usually necessitates the use of a
new connection box, and thus a modification of production to match
this new box. A change in terms of sealing the connection box also
involves the same effort/expense.
[0012] On the part of the manufacturer of the connection boxes,
such a change requires the development of a new connection box and
thus a changeover of the manufacturer's production process.
OBJECTS OF THE INVENTION
[0013] It is therefore an object of the present invention to
provide an improved solar-panel connection box.
[0014] Another object is the provision of such an improved
solar-panel connection box that overcomes the above-given
disadvantages, in particular that reduces the number of the various
connection boxes, in particular, of the various bases of the
connection boxes despite the variation in requirements.
SUMMARY OF THE INVENTION
[0015] A box for connecting an output conductor from a solar panel
with a feed cable has according to the invention a base mountable
on the solar panel and formed with a first hole for the
panel-output conductor and a second hole for the feed cable, a
removable cover fittable with the base in a closed position and
forming in the closed position with the base a substantially closed
compartment, and at least one component mounted on the cover in the
compartment.
[0016] A component within the scope of the invention is something
that affects transmission of electricity from the solar panel into
an electrical network connected to the feed cable, in particular, a
connector for electrically connecting the panel-output cable and
the feed cable. This can be a contact, a conductive track, a lead
frame, an element bridging two the panel-output cables such as a
diode, or an active or passive switching or control element.
[0017] In addition a component within the scope of the invention is
something that affects the microclimate inside the connection box,
in particular a heat-emitting element, a cooling plate, or a
gas-exchange element, in particular, a gas-permeable membrane or
sintered metal part or plug.
[0018] Using the cover closing the base as a mount for such a
component can help in reducing the multiplicity of different bases
for the connection boxes. The following example is provided to
explain circuit elements that affect the transmission of
electricity:
[0019] Prior-art connection boxes are known that couple multiple
panel-output cables to at least two the feed cables. In these
multipolar connection boxes, the typical approach is to bridge the
individual panel-output cables relative to each other by diodes so
as to ensure the flow of electrical current from the feed cable in
the event of a failure or when the solar cells are shaded. However,
multipolar connection boxes are certainly known in which shunt
diodes are not used. As a result, connectors that affect an
electrical connection with shunt diodes are missing in is these the
connection boxes.
[0020] If the manufacturer of solar panels using shunt-free
connection boxes wants to change over to connection boxes in which
shunt diodes can be employed, it has been necessary up to now to
install appropriate connectors in the base. Thus according to the
invention the cover used for the shunt-diode-free connection box
carries the shunt diodes, so this installation step can be
eliminated.
[0021] The advantages of the invention in regard to circuit
elements that affect the climate inside the connection box can be
described based on the following example:
[0022] As was already explained above, there are two different
techniques that protect the circuit elements inside the box from
damaging environmental effects such as contamination and moisture.
Encapsulating the circuit elements inserted in the compartment has
the fundamental advantage that the seal can be reliably ensured
using simple means. The fundamental disadvantage of this technique
is that no corrective action can be taken on the circuit elements
after the fact since these are solidly encapsulated by resin.
Replacement of a defective diode or fixing a poorly contacting
connection between the panel-output cable and the feed cable is not
possible without destroying the is connection box.
[0023] Connection boxes, whose compartment is protected against
environmental effects by a flexible seal between the cover and the
base do not have these disadvantages. However, since an air cavity
does exist inside the box, a microclimate forms in the box as a
function of the outside climate, with the result that condensation
or the formation of positive or negative pressures can occur inside
the box. These boxes must therefore be provided with a
gas-permeable element, such as, for example, a membrane or a
sintered-metal wall plug.
[0024] In particular when changing over from the encapsulation
technique to a box with an unsealed compartment, up until now it
was necessary to switch to a base with a gas-exchange element,
which action usually involved a changeover in fabrication due to
modified box dimensions. The cover according to the invention,
which based on the above-referenced embodiment can contain a
gas-exchange element, enables the previously employed box to be
reused without changing over the fabrication process in terms of
the design of the connection box.
[0025] Another embodiment of the invention is characterized in that
the above-mentioned cooling plate has thermal bridges that engage
heat-emitting components inside the compartment. In particular,
these thermal bridges are designed as elastic spring tongues. These
thermal bridges are integral with the cooling plate.
[0026] Providing the cover with a cooling plate to dissipate heat
generated inside the connection box creates another problem that
occurs in the prior art. Heat is emitted in currently used
embodiments of the connection boxes, in particular, by shunt
diodes, which in operation can reach a temperature of up to
180.degree. C. This heat negatively affects the solar cells of the
solar panel. A cover provided with a cooling plate, in particular,
as specified by the above-referenced design variants, makes it
possible to easily yet effectively retrofit existing connection
boxes in order to solve the temperature problem.
BRIEF DESCRIPTION OF THE DRAWING
[0027] The above and other objects, features, and advantages will
become more readily apparent from the following description,
reference being made to the accompanying drawing in which:
[0028] FIG. is a perspective view from below of the cover of the
box according to the invention;
[0029] FIG. 2 is a perspective view from above of the cover
box;
[0030] FIG. 3 is a view from above of an inverted alternate cover
box in accordance with the invention; and
[0031] FIG. 4 is a section taken along line IV-IV of FIG. 2;
[0032] FIG. 5 is a perspective view from above of a base of an
alternative embodiment of the connection box;
[0033] FIG. 6 is a perspective view from above of an inverted cover
for the base of FIG. 5;
[0034] FIG. 7 is a perspective view from above of the cover of FIG.
6 in its normal orientation;
[0035] FIG. 8 is a longitudinal section through a connection box
taken along line VIII-VIII in FIG. 5; and
[0036] FIG. 9 is a perspective view of a cover of another
embodiment of a connection box according to the invention.
SPECIFIC DESCRIPTION
[0037] As seen in FIGS. 1 and 2 a connection box 10 according to
the invention has a base 11 (FIG. 2) with a generally rectangular
and planar floor 12 and an annular side wall 13 that define a
compartment 14 serving to hold circuit elements. On two opposing
sides at its outer surface, the side wall 13 is provided with
guides 15 and projecting locking lugs 16. Below the locking lugs
16, the guides 15 have tool-guide slots 17. (The references to "up"
and "down" being purely for convenience of description, since the
box is often mounted inverted on the generally downwardly facing
back face of a solar panel.)
[0038] An inner wall 18 parallel to the outer side wall 13 is
provided inside the compartment 14 such that it is spaced relative
to side wall 13 by a circumferential gap 19 from the wall 13. The
side wall 13 and inner wall 18 each have aligned cable guide
cutouts or holes 20 through which a feed cable 21 passes. The feed
cable 21 conducts the electricity generated by the solar panel into
an electricity network, optionally through additional technical
equipment.
[0039] The base 12 has a hole or opening 22 through which
panel-output cables 23 are routed into compartment 14 of connection
box 10. These panel-output cables 23 are strip conductors whereas
the feed cable 21 is a standard cable with conductors held in an
outer insulating sheath.
[0040] The feed cable 21 has a stripped end 24 where its conductors
are mechanically reinforced by a cable end sleeve 25. A crimp ring
26 inward therefrom in the end 24 functions as part of a
strain-relief assembly. The floor 12 of the connection box 10 has
two approximately U-shaped ridges 27 extending perpendicular upward
from the floor 12. These ridges 27 form a holding seat 28 that is
centrally grooved. This groove receives the crimp ring 26 to take
up strain in the feed cable 21.
[0041] The end 24 provided with the cable end sleeve 25 of the feed
cable 21 extends across the opening 22 of the floor 12 and is
anchored at least on the opposite side in the compartment 28 of the
opening 22. To this end, two U-forming lugs 29 on the floor 12 form
a snap-in support for the cable end sleeve 25. In this case, the
cable end sleeve 25 also rests on a support ridge 40 extending
across the opening 22.
[0042] The panel-output cable 23 coming from the solar panel passes
through the opening 22 into the connection box 10 and over the end
24 of feed cable 21 such that it is partially wrapped around the
cable 11 end sleeve 25 in electrical contact therewith.
[0043] The floor 12 of the base 11 of the connection box 10 is
secured by its face turned away from the cover 30 to the solar
panel shown schematically at 68, in particular, by an adhesive bond
69. The opening 22 is in the region of a cutout in the solar-panel
housing through which panel-output cables 23 are routed to the
outside.
[0044] A cover 30 the of connection box 10 is illustrated in FIG.
1. It has a planar top wall 31 normally extending parallel to but
space from the floor 12 and provided with an essentially
circumferential collar 32 directed toward the base 11.
[0045] At opposite sides, locking lugs 33 facing the base 11
project from the cover 30 and each define a snap-in-locking opening
34. A circumferential overhanging rim 35 projecting from the cover
wall 31 opposite the collar 32 is formed near the locking lugs by a
tool-engagement formation 36. Similarly, the collar 32 has a cable
guide cutout 37. This corresponds in terms of its position with
cable guide cutouts 20 of the inner and outer side walls 13 and
18.
[0046] The bottom face of the cover wall 31 facing the base 11 is
provided with a contact 38 in the form of a clip spring 39 having
an approximately .OMEGA.-shaped cross-section.
[0047] When the box 10 is closed, that is, when cover 30 is mounted
on the base 11, the collar 32 fits in the base-section-associated
ring gap 19. To effect a gas-tight seal of connection box 10, a
seal (not shown), is provided. The lug guides 15 receive the
locking lugs 33 that are pushed over the wedge-shaped locking lugs
16 and grasp these from behind while locking the connection box 10
closed. The cable end sleeve 25 overlaps the clamping springs 39,
which engage in the overlap region of the panel-output cable 23 and
the end 24 of the feed cable 21, and are provided on the cover wall
31, when everything is closed. This ensures that panel-output cable
23 is held in a securely clamped fashion on the cable end sleeve
25.
[0048] The tool-engagement formations 17 and 36 function to allow
spreading and release of the snap-in-locking connection between the
locking lugs 33 and locking lugs 16, so as to allow the cover to be
removed from base 11.
[0049] FIG. 4 shows on the right the snap-in-locking connection
between the cover 30 and the base 11 by the locking lugs 33
grasping behind the locking lugs 16. Also shown is the insertion of
the collar 32 in the annular gap 19 is formed between the inner
side wall 18 and the outer side wall 13. The cable end sleeve 25
surrounds the core 41 composed of multiple conductors in the
illustrated embodiment and mechanically reinforces this core 41.
The panel-output cable 23 exiting the solar panel passes around the
cable end sleeve 25. This cable end sleeve 25 itself rests on a
lower support ridge 40 bridging the opening 22. The spring 39 grips
the panel-output cable 23 on the cable end sleeve 25, and holds the
panel-output cable 23 on the cable end sleeve 25 securely so as to
form a good electrical connection.
[0050] FIG. 4 clearly shows that only the cable end sleeve 25 of
the contact 39 functions as a support. The spring 39, panel-output
cable 23, and cable end sleeve 28 consequently form a
self-supporting connection arrangement.
[0051] It is within the scope of the invention that the clip 38 can
be mounted detachably on the panel-output cable 23 and cable end
sleeve 25.
[0052] In sum, a connection box 10 has been described that
advantageously provides an installation-friendly, secure electrical
connection between the panel-output cable 23 and the feed cable 21.
The need for tool to work on conductor elements and strip-conductor
structures inside the connection box has been eliminated. The
simple arrangement of the panel-output cable 23 directly on an
electrically conductive region of the feed cable 21 and the secure
connection by a contact that only needs to be fitted in place have
significant time and cost advantages for installing the connection
box, in particular, if the clip 38 is mounted on the cover 30 of
box 10 and the connection between panel-output cable 23 and feed
cable 21 are locked together by closing the box 10.
[0053] FIG. 3 shows a cover 50 of another embodiment of the
invention that corresponds with another unillustrated base. The
connection box 10, not shown in its entirety, of this second
embodiment is of multipolar design. This means that multiple
panel-output cables 23 exiting the solar panel are connected to two
feed cables 21 inserted into the connection box 10. In this case,
this involves a two-pole connection box 10 in which, analogously to
the previous description, one panel-output cable 23 is fitted on
each electrically conductive and mechanically reinforced end 24 of
a respective feed cable 21. Contacts 38 provided in the cover 50,
which here too are designed as clamping springs 39 with an
approximately .OMEGA.-shaped cross-section, ensure the good
electrical connection of the panel-output cables 23 and the ends 24
of the respective feed cables 21.
[0054] In the case of multipole connection boxes 10, panel-output
cables 23 are typically provided with shunt diodes 51. These
prevent the solar panel from heating up, whenever solar cells are
not operating in the case of parallel operation, for example, due
to shading, by preventing undesired current from flowing.
[0055] Unlike the prior art referenced in the introduction, the
shunt diodes are not inserted in the base using connection clamping
terminals, but are instead integrated in the cover 50 and
electrically connected to clamping springs 39 through their leads
52.
[0056] Since shunt diodes 51 in current applications are the main
cause of waste heat, the arrangement of the shunt diode in the
cover has significant advantages in thermal terms alone. The diode
is thus disposed directly adjacent the usually well-ventilated end
wall 31 of the cover 50 such that the waste heat can be effectively
dissipated. Dissipation of the waste heat can also be significantly
improved further by disposing large-area heat-sink plates, or at
least one heat-conducting plate 53 on the bottom side of cover wall
31. These cooling plates--also identified as heat sinks--are
connected through thermal bridges in this example leads 52, to the
body 54 of the diode 51, thereby further improving heat
dissipation.
[0057] In one development, not illustrated here, the diode body 54
rests directly on the cooling plate 53, diode body 54 then
preferably providing as large a support area as possible.
[0058] In sum, FIG. 3 illustrates an extremely advantageous
development of the invention by which problems caused by waste heat
from circuit elements supported inside the connection box 10 can be
eliminated.
[0059] The above-referenced connection box involves a new
development various circuit element have been eliminated from the
base. Except for the feed cable 21 attached inside the base 11 and
the panel-output cable 23, the base 11 does not contain any other
component. The purpose of compartment 14 is to accommodate the
circuit elements disposed on the cover 30.
[0060] In contrast, FIGS. 5 through 8 show a connection box 10 as
essentially known from prior art, the base 11 of which contains
various circuit elements.
[0061] The base 11 shown in FIG. 5 has threaded collars 55
surrounding cable guide cutouts, the collars having pinch-type
tongues 56 pointing away from the connection box 10, through which
the feed cables 21, not shown, are routed. After insertion of the
feed cables 21 through the cable guide cutouts 20, acorn nuts, not
shown here, that grasp the tongues 56 are screwed onto the threaded
collars 55, the acorn nuts pressing the tongues 56 into the
insulating sheath of the feed cable 21 and having a strain-relief
effect.
[0062] The connection box 10 shown in FIGS. 5 through 8 is a
multipolar connection box 10. This means that a plurality of
panel-output cables 23 are inserted into the compartment 14 and
electrically connected with respective strip-conductor structures,
not shown here. The individual the panel-output cables 23 are
coupled to each other through shunt diodes 51.
[0063] The cover associated with the base in FIG. 5 is shown in a
perspective view from below and above in FIGS. 6 and 7. The collar
32 here has an outwardly open circumferential groove 57 into which
an unillustrated seal such as an O-ring is inserted. When the cover
30 is mounted on the base 11, this O-ring seals the cover 30 and
the base 11 against each other, thereby creating a sealed air
cavity inside the closed connection box 10.
[0064] In order to equalize pressure between the outer climate and
the microclimate inside the connection box, the base 11 in FIG. 5
has a gas-exchange element identified as 58 in the form of a
sintered metal plug 59. The plug 59 is fitted in openings in the
side wall 13 and exposed to the outer environment. When the
connection box 10 is closed, tabs 60 of the cover 30 overlay these
openings in the side wall 13 to prevent contamination of them. In
this embodiment, the cover has two opposite tabs 60. Hence care
must be taken with the appropriate alignment of the cover 30 when
the connection box 10 is closed.
[0065] The connection box 10 shown in FIGS. 5 through 8 has a
special feature in regard to the cover. A heat-dissipating element
61 in the form of a cooling plate 62 (see FIG. 6) is provided on
the bottom of the cover 30, this element being shown in FIG. 5 in
the position it assumes when the connection box 10 is closed.
[0066] The cooling plate 62 receives heat from the shunt diodes 51
through thermal bridges 63 that are designed as elastic spring
tongues 64, the heat typically being carried away by the radiation
or conduction from externally well ventilated cover 30. The shunt
diodes 51 here represent any conceivable heat-emitting circuit
element.
[0067] In addition to the sintered metal vent plugs, the cooling
plate constitutes a second circuit element that affects the
microclimate inside the connection box 10. It is possible to
eliminate temperature problems in existing connection boxes by the
cover 30 as described here and carrying a circuit element and a
cooling plate 62
[0068] FIG. 9 shows another embodiment of the invention. Here again
a cover 30 carries a circuit element in the form of a gas-exchange
element 58. In this case, this also involves a sintered metal part
59 that is supported in a cover-associated holder 65. The part 59
is in contact with the outside climate through a groove 66 that
ends in openings 67 at the edge of the cover. This allows air to
move between the interior of the connection box 10 and the outer
environment, thereby preventing any positive pressure, negative
pressure, and in particular, the formation of condensation inside
the box.
[0069] The base of such a connection box 10 that was previously
utilized for the encapsulation technique can be easily used for
encapsulation-free sealing by the above-described cover 30 of FIG.
9.
[0070] In sum, mounting circuit elements in the cover 30 or 50
advantageously significantly reduces the design-related and
fabrication-related cost of fitting solar panels with the
connection boxes 10. Circuit elements within the scope of the
invention are defined as elements that inside the connection box 10
either have an effect on the transmission of electricity from the
solar panel to the public electrical network, or affect the
microclimate existing inside the connection box 10. Explicitly not
circuit elements are the seals between the cover 30 or 50, and the
base 11 of the connection box 10. These have no effect on the
transmission of electricity and also have similarly little effect
on the microclimate existing inside the connection box 10. On the
contrary, these types of seals are what create a microclimate
existing inside the connection box 10
* * * * *