Telephone Station Protectors
Model 1356

Balanced Operation - Heavy Duty

Replaces AT&T 125EW, Reltec R356VSR2, SPD356




The model 1356 gas station protector is designed to provide heavy duty transient and power fault protection for most standard telephone line applications. The common chamber, 3 electrode gas tube provides true balanced operation. An over voltage on either side of the circuit causes the entire tube to ionize and grounds both sides of the circuit simultaneously. This simultaneous grounding prevents a second arriving transient on the opposite side to pass through the equipment as may happen with 2 element configurations. This balanced configuration provides the best possible protection against line to line metallic surges where the transient on one side slightly lags the other. Nominal breakdown voltage for the model 1356 is 350VDC.

All station protectors come with an external fail-safe mechanism that ensures safe operation even under the most adverse conditions. Under continuous surge conditions, the device will short both sides of the circuit to ground.


The model 1356 station protector is well suited to single or dual pair applications in residences, rural locations, and other small pair count customer premise installations including Network Interface Devices. The model 1356 is designed to provide optimum protection against lightning surges, power faults, and other severe line hazards.

Features & Benefits

bulletHeavy duty surge handling capability
bulletModular industry standard design
bulletSuperior common chamber design
bulletBalanced operation
bulletUL 497 Listed
bulletRugged dependable operation
bulletFits most Network Interface Devices
bulletReduced service calls compared to 2 element designs
bulletPrevents damage by "lagging" or sneak transients
bulletDocumented safe performance



  DC Breakdown nominal)     Capacitance  
  @ 100 V/sec


 1 Vrms © 15HZ, 5OVD

 <1 pf

Impulse Breakdown Voltage   Insulation   Resistance  



>100M ohms



 DC Holdover Voltage

 135V; <150rms

 Fail-safe Operation  

 <50 sec

Surge life (min operations)1,2    @5.0A

<15 sec

 @10, 10 x 1000 Ásec




 @100A, 10 x 1000 Ásec


 @60 A

<3 sec

 @10kA, 8 x 20 Ásec


 @20kA 8 x 20 Ásec


Current Limiting (-PTC)  
 @65Arms, 11 cycles, 130A total


Hold current (mc) @ 20C =


@10Arms, 1 sec, 20A total


 R min/R max ohms


Designed and tested to meet requirements of UL 497A, REA PE8O, and Bellcore TR-TSY-000070, 000071

1surge rating is 2x with respect to ground during a simultaneous surge
2service life requirement as per Bellcore TR-NWT-0001361


1.2"H x 2.25"W x 1.5"D - .08 Lbs.

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