Museum of Plugs and Sockets: types xxx

DDR made fuses
(German Democratic Republic)

distrib.
board

general
nfo

From the early 1930s D-type fuses were the standard domestic electrical safety devices in Germany and many other continental European countries. D-type fuses existed in seven different body sizes*, each with a range of current ratings.
* DI (D-one), DII, DIII, DIV, DV, D0 (D-zero), and in DDR only: DL.
See English and German Wikipedia for additional information.

D-type fuses were necessary not only for distribution units in new homes, but also for replacing blown fuses. Shortly after World War II supply of fuses was limited, among others because of shortage of raw materials. Moreover several electrical companies in East Germany were severely hit by Soviet Russian reparations. Ingenuity was necessary.

All items in boxes A - I have been donated by Peter Martin, Zwickau, Sachsen.
Sizes, in italics, are given in millimeters.

Colors are based on
Germania postage stamps introduced in 1900.

DL-type fuses

Genuine DDR made fuses for domestic purposes. Size of porcelain body is approx. 65% smaller than DII fuses (box D). and colored release indicator is lacking. Instead, colored rings indicate the rating. The simpler design saves material.
For an unknown reason the 6A fuse has the same size cap as 10A fuse (both 8 mm) instead of 6 mm.

DL fuses fit in E 16 fuse holders (see box H)

Each of the fuses in boxes A, B, C and D have been made by VEB Elektroinstallation in Sondershausen, Sachsen (part of VVB IKA für Installationen, Kabel und Apparate in Leipzig). The company used a flash symbol, visible on each metal end caps.

Unclassified D-type fuses

Type of space- and material-saving fuse unique for the DDR. The fuse rating, indicated on the metal end cap of 4, 6,3 and 10 A fuses is preceded by T, which means träge (slow) fuse.

The far right fuse has an uncommon low rating of 0.4 A.
It is unknown for which type of application the very low current rating could be used.

DI-type fuses

Fuse length is identical to DII (see box D), but width of the porcelain body is smaller (13 versus 22 mm).
DI fuses fit in E 27 fuse holders (width adapter is advisable).
DI is late 1920s introduced as "Sparpatrone" (save cartridge), but no longer used anymore in new distribution boards.

The triangle-1 symbol is a DDR quality mark issued by TGL;
1 states for "good" quality.

Snake symbol on 2 and 20 Amp fuses is often used to indicate slow fuses.

DII-type fuses

DII was the most used domestic D-type fuse. The DDR started DII production in the 1980s, probably mainly for export. Income of hard currency was welcome. T and snail's shell indicate a slow fuse.

Marks on bottom cap: IKA Sondershausen logo, and five certification marks: TGL quality 1 (DDR), VDE (BRD), DEMKO (Denmark), NEMKO (Norway) amd SEMKO (Sweden).

D0-type (Neozed) fuses

Neozed, designed by Siemens in 1967 as a more efficient alternative to DII. The reduced size results in less loss of heat and fits in a more compact fuse holder.
Three sizes exist: D01 is 11 mm wide; D02 15 mm; D03 22 mm and 43 mm long.
D01 is nowadays uncommon and D03 is rarely used anymore.

Shown D01 fuses have been used, but not made in the DDR. Manufacturer of 6A plug is Kaposvári Villamossági Gyár (factory of electrical equipment in Kapsovár, town in Hungary).
Manufacturer of 10A and 16A fuses is ETI Elektroelement in Izlake, Slovenia.

F	DV-type fuse These large, outdated fuses exist for 125, 160 and 250 Amp. DV fuses are still available for replacement.		Manufacturer: Krania, trade name of VEB Elektroinstallation Kranichfeld (town in Thuringia, close to Weimar).
G	Automatic screw circuit breaker. Porcelain D-type fuses, shown in boxes A-F, have a metal wire that melts due to heat generation by excessive current flow. A broken wire can't be replaced; the fuse must be replaced. A screw circuit breaker has a bimetallic strip consisting of two layers of different metals. Increase of temperature results in an unequal mechanical displacement. One strip bends more than the other, resulting in a loss of contact between the two strips. Consequently the electrical circuit is interrupted.		An additional mechanism ensures that the connection remains broken. To restore the connection the black button has to be pressed down. Pressing the red button breaks the circuit manually. Red stripe (arrow) corresponds to the 10A rating. The device has three marks: (1) TGL quality mark (triangle 1); (2) logo of manufacturer VEB Elektroinstallation Annaberg; (3) circle with five-pointed star polygon, significance is unknown.

Fuse holders

Ceramic fuse holder with E 27 screw cap suitable for 50 mm DI and DII fuses. See distribution board page for more examples.
Manufacturer: Vogtländische Elektro-Industrie, Specialfabrik der Elektrotechnik in Plauen, Sachsen.

Ceramic E 16 fuse holder with phenoplast resin front, suitable for 36 mm DL and D01 fuses. Width of D02 fused is too wide to fit. Manufacturer: VEB Elektroinstallation Sondershausen.

Circuit breaker

Example of a modern circuit breaker that are nowadays used in home distribution boards. Such circuit breakers consist of a switch connected to a bimetallic strip (comparable to automatic screw circuit breaker shown in box G) or an electromagnet.
How Stuff Works describes the working functioning clearly.

DSKR (see green text) means DDR Schiffs Revision und Klassifikation = ship classification organization; non-governmental organization certifying that establishes and maintains technical standards for the construction and operation of ships (see en.Willipedia or de.m.Wikipedia for details).

The shown circuit breaker has two marks.
A company that has used the EAW logo could not be traced.
Please contact the museum if if you recognize the company that used the EAW logo.
DAMW* mark: housing is made by Zelbina Plasterzeugnisse (L37), Dresden; using melamine reinforced with cellulose (152).

* German Office for Measurements and Product testing
(find details on German Wikipedia page).

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