GRAM- Load Break Switching with Integral Ground Position

G&W Electric GRAM padmount and vault switchgear features load break switching capability with visible break and integral ground position in a totally sealed, submersible, dead front device. The integral ground position eliminates the need to handle any high voltage connections to ground the cable. The switches are designed for use on 3-phase systems with voltages up to 38kV and 900A load break and continuous current. These switches are extremely flexible and are offered in many different styles. Switches are typically sold with the switch operators on the front side. The high voltage connections can be positioned on the bottom, top, or side to ease cable training and installation.

The switches are designed to IEEE C37.71 and C37.74 for load break capability. Padmount enclosures are designed and tested to IEEE C57.12.28 and C57.12.29.

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Features and Benefits

Construction - Available compact construction with front accessible switch operators and bushings. Vault construction is also available with top or bottom bushings or top access to operators and bushings.

Visible Break - All ways are equipped with visible break to view the open, closed, and ground positions.

Ground Position - Integral ground position on all ways to eliminate the need to handle high voltage components to ground the cable.

Voltage Sensing - Available integral voltage sensing for use with voltage indication panel to determine in-phase condition or for use with a relay with up to 1% accuracy.

Automation - Available for motor automation with portable or permanently mounted motor and controls. A variety of relays such as SEL, ABB, and GE are available with G&W Electric programming and cabinet construction. Cabinets can be ordered in a low voltage enclosure for padmount, pedestal or IP68 rated submersible for vault installed switchgear. Programming for automatic source transfer, or LaZer custom solutions are available.

Configurations Chart for GRAM

# of Ways	One-line Diagram (Horizontal)	Voltage Class (kV)	Close Into Fault (kA asym)/strong>	Catalog Number	Approximate
# of Ways	One-line Diagram (Horizontal)	Voltage Class (kV)	Close Into Fault (kA asym)/strong>	Catalog Number	Width* in. (mm)	Wt. w/SF6 lbs (kg)
2		15	32	GRAM21-376M-40RP	29 (737)	700 (318)
		15	40	GRAM21-376M-40PI	32.5 (825)	600 (270)
		25	32	GRAM21-386M-40RP	29 (737)	700 (318)
		25	40	GRAM21-386M-40PI	32.5 (825)	600 (270)
		35	32	GRAM21-396M-40RP	29 (737)	700 (318)
		35	40	GRAM21-396M-40PI	32.5 (825)	600 (270)
3		15	32	GRAM33-376M-40RP	40.5 (1029)	950 (431)
		15	40	GRAM33-376M-40PI	62.25 (1580)	1400 (635)
		25	32	GRAM33-386M-40RP	40.5 (1029)	950 (431)
		25	40	GRAM33-386M-40PI	62.25 (1580)	1400 (635)
		35	32	GRAM33-396M-40RP	40.5 (1029)	950 (431)
		35	40	GRAM33-396M-40PI	62.25 (1580)	1400 (635)
4		15	32	GRAM44-376M-40RP	52 (1321)	1200 (544)
		15	40	GRAM44-376M-40PI	80.5 (2045)	1800 (815)
		25	32	GRAM44-386M-40RP	52 (1321)	1200 (544)
		25	40	GRAM44-386M-40PI	80.5 (2045)	1800 (815)
		35	32	GRAM44-396M-40RP	52 (1321)	1200 (544)
		35	40	GRAM44-396M-40PI	80.5 (2045)	1800 (815)
5		15	32	GRAM55-376M-40RP	63.5 (1613)	2500 (1136)
		15	40	GRAM55-376M-40PI	98.75 (2510)	2200 (1000)
		25	32	GRAM55-386M-40RP	63.5 (1613)	2500 (1136)
		25	40	GRAM55-386M-40PI	98.75 (2510)	2200 (1000)
		35	32	GRAM55-396M-40RP	63.5 (1613)	2500 (1136)
		35	40	GRAM55-396M-40PI	98.75 (2510)	2200 (1000)
6		15	32	GRAM66-376M-40RP	75 (1905)	2600 (1182)
		15	40	GRAM66-376M-40PI	117 (2970)	2600 (1180)
		25	32	GRAM66-386M-40RP	75 (1905)	2600 (1182)
		25	40	GRAM66-386M-40PI	117 (2970)	2600 (1180)
		35	32	GRAM66-396M-40RP	75 (1905)	2600 (1182)
		35	40	GRAM66-396M-40PI	117 (2970)	2600 (1180)
For rotary puffer (RP): Tank depth= 25" (635mm), Tank height = 27" (686mm)
For linear puffer (PI): Tank depth= 34" (865mm), Tank height = 32" (815mm)
*Dimensions are approximate and do not include entrances, gauges, frames, or operators

Ratings Chart for GRAM

Voltage Class	15kV	25kV	35kV
Maximum Design Voltage	15.5kV	27kV	38kV
Impulse Level (BIL)	110kV	125kV	150kV
One Minute Withstand	35 AC kV	60 AC kV	70kV
One Minute Withstand, Protection Test Rating	34 AC kV	40 AC kV	50kV
15 minute withstand	53 DC kV	78 DC kV	103kV
** Continuous and load break current	630 Amps	630 Amps	630 Amps
Momentary current	40kA asym	40kA asym	40kA asym
* Fault-close current (3 times)	40ka asym	40ka asym	40ka asym
One second current	25kA asym	25kA asym	25kA asym
Mechanical endurance, operations	2000	2000	2000
* Rating shown for Linear Puffer, Rotary Puffer limited to 32kA asym
** Available at 900Amps