Guard I
Guard I noise isolation transformers provide common mode noise attenuation and transverse mode noise attenuation.

Guard II
Guard II noise isolation transformers provide common mode noise attenuation plus an enhanced level of transverse mode noise attenuation for increased protection of sensitive electronic equipment.

Guard I Features
Features
• Grounded copper electrostatic shield between primary and secondary   winding
• 120dB common mode noise rejection
• 30dB transverse mode noise rejection
• Three-phase
• Compliance with ANSI and NEMA standards
• 220C insulation system
• Electrostatic shield ground wires are terminated to a common ground lug
• UL Listed
• ABS(American Bureau of Shipping) Type Approved
• NEMA 2 powder-coat drip-proof enclosure is standard. Weathershield kit is available for conversion to NEMA 3R   outdoor.
• NEMA 3R stainless steel enclosure is available up to 150kVA. To specify a stainless steel enclosure, substitute an   "S" in the fourth character in the GE catalog number. Example 9T83B3874 changes to 9T83S3874.

Applications
• Retail stores
• High lightning strike areas
• Small computer installations
• Marine and Offshore - ABS Classed Vessels

Guard II Features
Features
• Grounded copper electrostatic shield between primary and secondary winding
• Noise suppressors and spike/surge suppressors
• 120dB common mode noise rejection
• 60dB transverse mode noise rejection
• Single and three-phase ratings
• Compliance with ANSI and NEMA standards
• New lower TP-1 sound levels below ANSI limits
• 220°C insulation system
• UL listed
• ABS(American Bureau of Shipping) Type Approved
• NEMA 2 enclosure

Applications
• Schools and colleges
• Large computer installations
• Small commercial offices
• Motor installations
• Process controllers
• Hospitals
• X-ray rooms
• Electrical laboratories
• High lightning strike areas
• Marine and Offshore - ABS Classed Vessels

GE gives you a choice in power quality transformers, so you can choose the one that best fits a particular situation and application. Typical choices are shown below.