EDCO TECHNICAL BULLETIN 10590
COHP (FS) Primary Protectors (UL 497)
GENERAL INFORMATION (PRIMARY PROTECTORS)
COHP (FS) SERIES protectors have a dual UL listing. This enhances the flexibility and cost economy available to the user. Site-related paranieters called out in Article 800-30 of the NEC (National Electrical Code) govern whether the protectors are to be installed as
PRIMARY PROTECTORS (UL497) or as ISOLATED LOOP CIRCUIT PROTECTORS (UL497B). This section of the code is printed herein for your convenience. This instructional booklet describes PRIMARY PROTECTOR (UL497) installation only. Refer to TB 13090 for installation as an ISOLATED
LOOP CIRCUIT PROTECTOR (UL497B).
The COHP (FS) SERIES protectors are available in four standard voltage ratings. To properly select a
COHP for a given application, one must
FIRST know the maximum peak operational voltage on the pairs to be protected. Next,
ADD four volts to that number, and then SELECT the
COHP with a voltage sulfix equal to or higher than the calculated number. An example: we determine that the maximum peak operational voltage is 24 volts. Then, adding four to that number yields a selection voltage minimum of 28 volts. The proper
COHP would be a
COHP-O3OFS as a PRIMARY PROTECTOR.
*For Effective Protection
1. Protectors must be keyed properly on the 66 block. This is accomplished during initial installation by placing the grounding bar (MGB) on the
OUTSIDE PLANT (unprotected) side of the block.
2. A local (at protected equipment) single point ground must be established. This is illustrated later in detail.
*Protectors are installed in place of bridging clips on a standard split 66M1 -50 block. One ground rail (MGB) is required for each
*Never install telephone wiring during a lightning storm.
*When used as PRIMARY PROTECTORS: protectors must be installed in a UL recognized housing in order to be considered a UL-Compliant installation.
DETAILED INSTRUCTIONS COMMON FOR ALL INSTALLATIONS
1. Position the MGB parallel to the outside plant side of the M block.
2. Insert end hook around outside fanning strip of M block and gently pull into place, aligning angle brace as shown
3. Using mounting hardwdare provided, attach other end of MGB to M block mounting tab.
4. Tighten mounting screw once MGB is aligned parallel to M block.
5. Connect ground wire to ground lug. Use at least a #10 gauge wire. Bond protection ground according to recognized procedures.
6. Simply plug in the COHP module on M block and MGB. Thc module replaces the T & R bridging clips. It is suggested to line up the ground rail connector clip first.
National Electric Code Wording
SPECIFIC INSTRUCTIONS FOR PRIMARY PROTECTOR INSTALLATION
Mounting and Housing
For use as a UL-compliant primary protector, a mounting and housing arrangement described below is mandatory. The protectors must be mounted on a UL recognized 66 type block (ref: Siemon S66M1-50) inside a UL recognized enclosure (ref: Square'D type 12124B or
equal) for indoor or outdoor use. Note that two 66 blocks are used for each group of 25 cable pairs so that the required fusible wire link can be installed between the blocks as shown in Figure 2. INPUT cable using 22 or 24 AWG solid conductors, which meet local code
requirements, and OUTPUT cable using 24 AWG solid conductors, also meeting local code requirements must be used as cabling termination to box. INPUT cable is that which enters from outside building. OUTPUT cable is that between protector box and protected equipment. If the INPUT
wire size is 22 AWG, then 24 or 26 AWG solid copper wire with thermoplastic insulation may be used as the fusible wire link. If the INPUT wire size is 24 AWG, then 26 AWG copper wire (ref: Belden #9976) with thermoplastic insulation must be used as the fusible link. UL recognized
bushings (ref: Heyco #2119) must be used at the two cable entry and exit holes in the protector enclosure.
The INPUT cable sheath and the MGB grounding bar lug must be connected to a ground wire (6 AWG preferred) and run to the single point ground referenced in Figure 3. Grounding wires should not be run in metal conduits.
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