MDR
Mercury Displacement Relay Modules
The MDR series, utilizing premium quality mercury displacement relays,
offers the most robust, reliable, and durable switching technology available today. These
industrial strength modules are an excellent choice when the utmost in durability and
performance is required. A properly sized mercury relay will reliably handle millions of
heavy-duty operations.
Their ability to handle difficult loads and high in-rush currents
surpasses any electro-mechanical relay and their ability to withstand adverse electrical
conditions is far superior to any solid-state relay. They are well suited for building
automation, industrial applications, commercial displays, themed attractions, and other
venues with continued frequent use.
Mercury relay operation is quieter than traditional electro-mechanical
relays, while they still provide positive air-gap isolation. They also produce
significantly less EMI and RFI and are therefore a good choice for environments that are
sensitive to electrical noise.
The MDR modules are offered in single, dual and triple 10A
configurations for cost efficient handling of small to medium sized loads. Single 35A and
60A configurations are offered for larger loads and especially demanding applications.
| Model |
Description |
Module
Spaces |
| MDR10/1 |
1 x 10A Mercury Relay Module |
1 |
| MDR10/2 |
2 x 10A Mercury Relay Module |
1 |
| MDR10/3 |
3 x 10A Mercury Relay Module |
1 |
| MDR35 |
1 x 35A Mercury Relay Module |
1 |
| MDR60 |
1 x 60A Mercury Relay Module |
1 |
Specifications
MDR10/1, MDR10/2, MDR10/3, MDR35, & MDR60
1. The switching modules shall be the PWR Series MDR10/1, MDR10/2,
MDR10/3, MDR35, or MDR60 as required by the circuit layout.
2. The modules shall employ single pole, single throw, normally open (SPST-NO)
mercury displacement relays. Electro-mechanical or solid-state relays shall not be
acceptable.
3. The relay mechanism shall be housed in an encapsulated hermetically
glass-sealed stainless steel tube containing inert gas for arc quenching. The relays shall
utilize a ceramic plunger to displace mercury in order to create a new contact surface
with each operation.
4. All internal wiring shall be rated at minimum 125° C.
5. The relay contact resistance shall not exceed 4mOhms for its entire service
life.
6. The relays shall have a minimum breakdown voltage of 5000V contacts to ground
and 2000V between contacts.
7. 10A and 35A relays shall provide a mechanical life of at least 25 million
cycles and an electrical life of at least 8 million cycles at 120VAC with full load. 60A
relays shall provide a mechanical life of at least 10 million cycles and an electrical
life of at least 3.5 million cycles at 120VAC with full load.
8. The air-gap mechanism of the relays shall meet and exceed the requirements of
UL1472.
9. The module load circuit surge and transient withstand capability of the relays
shall meet and exceed the recommendations of ANSI C64.21-1991 for Location Category B,
Exposure Level 3.
10. Line and load terminals shall accept up to #8AWG wire for 20A modules, up to
#4AWG wire for 35A modules, and up to #1/0AWG wire for 65A modules. Control wiring shall
be provided by a 24" harness factory terminated in a 4 position keyed plug-in header.
11. The modules shall be UL listed for continuous operation at 100% of their
rating per NEC 1999 Article 210-20-a. Systems failing to meet this requirement shall not
be acceptable.
12. The modules including their wiring, termination points, mounting hardware,
enclosure and controller shall be UL and cUL listed as a complete assembly and for
Canadian installations comply with CSA Standard C22.2 #14-M91. UL recognized or listed
devices alone shall not be acceptable unless documentation is submitted to verify that the
entire assembly, including the controller and enclosure, has been tested and evaluated by
a Nationally Recognized Testing Laboratory (NRTL) and found to meet all the
herein-mentioned standards and requirements.
13. The modules shall be listed with the following minimum UL and cUL ratings per
pole at 40° C ambient temperature:
MDR10/1, MDR 10/2,
MDR 10/3
|
| General Purpose |
10 A |
@ |
277 Vac |
| DC |
10 A
5 A
3 A |
@
@
@ |
48 Vdc
120 Vdc
240 Vdc |
| Tungsten |
10 A |
@ |
120 Vac |
| Motor |
1/4 hp |
@ |
240 Vac |
MDR35
|
| General Purpose |
35 A |
@ |
277 Vac |
| DC |
35 A
17 A
10 A |
@
@
@ |
48 Vdc
120 Vdc
240 Vdc |
| Tungsten |
35 A |
@ |
120 Vac |
MDR60
|
| General Purpose |
60 A |
@ |
277 Vac |
| Resistive |
60 A
60 A
30 A |
@
@
@ |
277 Vac
48 Vdc
120 Vdc |
| Tungsten |
60 A
60 A
30 A |
@
@
@ |
277 Vdc
48 Vdc
120 Vdc |
| Motor |
3 hp
5 hp
5 hp |
@
@
@ |
120 Vac
240 Vac
277 Vac |
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