Schneider Electric 9070 manual Fuse Protection, Matrix for Choosing Proper Fuse Configuration

Industrial Control Transformers

Fuse Protection

FUSE PROTECTION

UL Standards and the National Electric Code require primary protection for Control Transformers, and many applications require secondary protection. Historically, the fuse options supplied by transformer manufacturers were designed for Line-to-Line primary (480 V) and Line-to-Neutral secondary (120 V).

Schneider Electric’s new line of fuse options lets customers obtain both factory installed and field installed fuse blocks. Factory installation saves you time and labor. For both options, the transformer footprint is identical to a Type T or Type EO transformer of equivalent voltage, because the fuse block is mounted above the transformer or on the transformer terminal blocks. This frees up space normally used by separate fuse blocks.

Schneider Electric offers the most complete offering of fuse options to meet all applications for protection of the transformers and load applications. These are broken down into Line-to-Line and Line-to-Neutral protection options for both primary and secondary. Due to space limitations of the transformers, not all options are available for every VA size. Also, all fuse blocks supplied by Schneider Electric are 30 amp fuse blocks, which limits the VA for each voltage.

All primary fuse blocks supplied by Schneider Electric require rejection style fuses. Rejection style fuses offer 100,000 AIC protection to comply with UL Standards. (Non-rejection style primary fuse blocks are available by request only and can be quoted through your Schneider Electric field sales office.)

	Primary			Secondary
	VA Range without	VA Range with			VA Range with
Voltage			Voltage		Secondary
	Primary Protection	Primary Protection
					Protection
550/575/600	25–5000 VA	25–5000 VA	277		25–5000 VA
440/460/480	25–5000 VA	25–5000 VA	220/230/240		25–5000 VA
380/400/415	25–5000 VA	25–5000 VA	208		25–5000 VA
277	25–5000 VA	25–3000 VA	110/115/120		25–2000 VA
220/230/240	25–5000 VA	25–3000 VA	48		25–1000 VA
208	25–5000 VA	25–2000 VA	24		25–500 VA
110/115/120	25–2000 VA	25–1500 VA	12		25–250 VA

Matrix for Choosing Proper Fuse Configuration

			Primary Line-to-Line			Primary Line-to-Neutral	Primary Without
							Protection
	Secondary Line-to-Line	No factory installed option				Type TF with R12	S22
	Secondary Line-to-Neutral			Type TF		Type TF with R11	S12
	Secondary Without Protection			Type TF with R02		Type TF with R01	Type T product line
Primary voltages requiring Line-to-Line protection:						200/208/220/230/240/380/400/
						415/440/460/480/550/575/600
Primary voltages requiring line-to-neutral protection: 100/110/115/120/277/347
						Europe: 220/230/240
Secondary voltages requiring line-to-line protection:						208/220/230/240
	Secondary voltages requiring line-to-neutral protection: 120/277
						Europe: 220/230/240
	NOTE: The following secondary voltages could be either line-to-line or line-to-neutral: 12/24/48
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08/2005					© 1999–2005 Schneider Electric All Rights Reserved