GE-8920-PS-DC Intrinsically‑Safe DC Power‑Supply Module

Description

Core performance features

Input voltage range: 18.5‑36 VDC (nominal 24 VDC). Output: 12 VDC ±5 %, rated maximum output current 5 A. Input‑output galvanic isolation test voltage 1500 V AC rmsEaton. Supports parallel load‑sharing, two or more 8920‑PS‑DC can run together to realize power redundancy and expand total power capacity. Built‑in comprehensive protection: over‑voltage, over‑current, short‑circuit protection on both input and output sides. Approval certificates: ATEX Zone 2, IECEx, FM for Class I Div 2 hazardous locations, meets SIL‑2 related requirements for safety‑system auxiliary power supplyEaton. Mounting requirement: must be installed on dedicated carrier base 8724‑CA‑PS, cannot be directly clipped onto standard DIN‑rail. Environmental parameters: operating temperature ‑40 ~ +70 ℃; storage temperature ‑40 ~ 85 ℃; IP20 degree, only for inside control cabinet. Module weight approx 1290 g; dimension 84 mm × 110 mm × 160 mm. Wiring terminals: two‑part detachable screw terminals, maximum cable cross‑section 2.5 mm²; duplicated input terminals for convenient redundant power access.

Physical appearance

Metal‑cased rectangular power‑supply unit, not thin plug‑in I/O card. ‑ Front panel: several LED status lamps for power input, output status and fault alarm; part‑number label printed 8920‑PS‑DC. ‑ Side: detachable two‑part screw terminal blocks for DC power wiring. ‑ Back: locking mechanical structure for fastening onto 8724‑CA‑PS carrier base. ‑ No golden‑finger backplane connection; power transmits through carrier base to SafetyNet rack internal bus.

On‑site application scenarios

Mainly deployed in petrochemical and chemical plant SIS cabinets. It supplies safe 12 V power for SafetyNet CPU such as 8851‑LC‑MT and intrinsically‑safe I/O modules. If this power module fails, the corresponding rack I/O and controller will lose power, possibly triggering safety‑system trip. After replacement, no program modification is needed. Verify input voltage, output voltage value and load‑sharing status before online running.

Installation & operating notes

Must use matching carrier base 8724‑CA‑PS for mounting. Do not install on ordinary DIN‑rail without carrier. Signal and power wiring should keep physical separation from high‑power cables, reduce electromagnetic noise. When configuring redundant parallel power supplies, confirm load‑sharing function is activated. Maintain cabinet ventilation; high ambient temperature will derate output capacity. Do not open metal housing on‑site. Replace whole unit for permanent hardware damage; component‑level repair will invalidate hazardous‑area certification.

Common field phenomena & disposal thoughts

1. Power indicator off: Check 18.5‑36 VDC input voltage and terminal locking. If input is normal, internal power‑circuit damage is suspected.
2. Output voltage drop under load: Confirm total rack I/O load current does not exceed 5 A rating. Check cabinet high‑temperature derating influence.
3. Module over‑current alarm: Inspect short‑circuit fault on back‑plane bus or I/O module. Eliminate field short‑circuit point.
4. Abnormal load‑sharing between parallel power units: Confirm parameter setting for load‑sharing function. Clean terminal contact oxidation.