MTA MTC CONTROL POWER TRANSFORMERS - Eaton

1 9-1 July 1999 CONTROL POWERTRANSFORMERS Industrial CONTROL TRANSFORMERS Table of Contents DescriptionPageNumbering System .. 9-2 CONTROL POWER Selection Data .. 9-3 C341 Kits (include fuses and wiring) .. 9-4 MTA .. 9-5 MTC .. 9-7 AP .. 9-9 Wiring Diagrams for MTA, MTC and AP TRANSFORMERS .. 9-10 MTE/MTG .. 9-11 MTK .. 9-17 CE Marked TRANSFORMERS .. 9-19 Wiring Diagrams for MTE, MTG, MTK and CE Marked TRANSFORMERS .. 9-24 Transformer Kits Include Fuses and WiringType MTE, MTG, MTA and MTC TransformersType AP TransformersCE Marked TRANSFORMERS 9-2 1999 CONTROL POWERTRANSFORMERS Industrial CONTROL TransformersCatalog Numbering System a Industrial CONTROL TRANSFORMERS , CE Marked CONTROL TRANSFORMERS , Kits NOTE: Contact your local Cutler-Hammer sales office for voltage combinations not shown.

2 Use table for catalog number breakdown only. TypePrefixVA RatingCodeTransformer DesignCodePrimary VoltageSecondard VoltageCodeModificationsCode Industrial CONTROL TransformerCE Marked CONTROL TransformerIndustrial CONTROL Transformer Kit (Transformer, Fuses, Wiring)CCEC34125507510015020025030035050 075010001500200030005000 Type AP Only: 3000500075001000015000002500500075010001 5002000250030003500500075010001500200030 00500000030005000700100015 MTAMTCMTEMTGMTKAPACEGKP120 x 240240 x 480, 230 x 460,220 x 440240 x 480240 x 480230/460230/460220/380/440/550,230/400 /460/575,240/416/480/600208/230/400/460/ 575208/230/400/460/575208/277115230/460/ 575208/380/416500/575/600380/400/415380/ 400/415550/575/600200/220/440, 208/230/460,240/480240/416/480/600,230/4 00/460/575,220/380/440/550,208/500240 x 48024120/115/11024120 X 240115115/23023/110, 24/115.

3 25/12024/115/230115/23012024115/95115/95 110/115/120110 x 22022/23/2422/23/2423/110, 24/115, 25/12099/120/130, 95/115/125,91/110/120,85/100/110120/2401 B2A2B2C2F2G2U2V2W3A3B3C3D4C4D4H4W5E6U7G (Type AP Only) Type MTE/MTG/MTK Factory mounted 2-pole primary fuse block for rejection type fusesFactory mounted2-pole primary fuse block for non-rejection typefusesSecondary fuse clipsfor 1/4 x 1-1/4 inchfusesNo Secondary fuse clipsRing type terminalsconnection tofuseblockElectrostatic shieldFactory mounted finger-safe terminal shields Type AP Bottom mountedSide/wall mountedElectrorstatic shieldCopper windings Type MTA/MTC Factory mounted 3-pole fuse block (2-pole primary rejection type with 1-pole secondary non-rejection type)

4 Electrostatic shieldLead terminationsFBFBNQXXRTESFSBSESCUFBESL 9-3 July 1999 CONTROL POWERTRANSFORMERS CONTROL Transformer Selection Procedure The following steps will assure that the secondary voltage delivered by your transformer will be either 85%, 90% or 95% of the nameplate sec-ondary voltage under maximum inrush conditions, at rated input volt-age. A typical selection example based on these steps follows. Step 1 Calculate the total SEALED (steady state) VA load of your CONTROL circuit. This is done by adding the continu-ous VA requirements of the maxi-mum number of components that will be energized at any given time, including non-inductive as well as inductive components.

5 For Sealed VA data see Page 12-6 . Step 2 Calculate the PEAK INRUSH VA of your CONTROL circuit. First, analyze the sequence of operation of all components. Then add together the inrush VA ratings of the components that will be energized simulta-neously. Next, determine the peak or maximum simultaneous inrush VA load that the transformer will see. The VA requirements for indi-cating lights, timers and other non-inductive components which do not have an inrush VA also should be included since they will present a load to the transformer at the time of maximum inrush.

6 Step 3 Calculate the TRANSFORMER SELECTION INRUSH VA. Use the fol-lowing formula: NOTE: Transformer Selection Inrush VA also can be determined by add-ing the inrush VA and sealed VA arithmetically, but this usually results in an oversized transformer. Step 4 Determine the correct transformer NAMEPLATE VA RATING. Refer to the Inrush/Regulation Data table: If the line supply to the transformer is fairly stable (does not vary more than 5%), use the 90% secondary voltage column the 90% column is most commonly used. If the line supply voltage varies up to 10%, use the 95% voltage regulation column.

7 To determine the correct VA trans-former rating, go down the column until you arrive at the inrush VA rat-ing closest to, but not less than, the Transformer Selection Inrush VA calculated in Step 3. The left hand column of the table will give the corresponding transformer NAME-PLATE VA RATING. Inrush/Regulation Data NOTE: When evaluating supply-line stability, remember that supply-line voltage drop frequently is associated with motor-starting inrush current. When motors and motor controls are connected to a common feeder, the controls will experience a momentary voltage dip when the motor starts.

8 This reduces the con-trol transformer voltage supplied to the motor starting contactor and may cause the contactor to chatter or drop out. Selection Example Steps 1 and 2 By following Steps 1 and 2 described in column one at left, analysis of the CONTROL circuits shows the following sealed VA and inrush VA data: Step 3 Following Step 3 in column one at left, the Transformer Selection Inrush VA is calculated at 1773 VA. Transformer Selection VA = = (VA Sealed) 2 + (VA Inrush) 2 = = (311) 2 + (1773) 2 = = 3,240,250=1800 Steps 4 and 5 Following Steps 3 and 4 at left, the Inrush/Regulation Data Chart is then consulted to find the correction name-plate VA size of the transformer.

9 Under the 90% Secondary Voltage column, we find that a 320 VA transformer will deliver 2224 VA, amply covering circuit demands of 1880 Inrush VA. Checking this selection against the requirements of 311 VA sealed, we confirm that a 320 VA transformer will be sufficient. TransformerVA Rating55 CInrush VA 40% POWER FactorAt 95%SecondaryVoltageAt 90%SecondaryVoltageAt 85%SecondaryVoltage 6095105180225137242294592929185329407842 1312227409512107116632753203805508501271 1581212431965500180122243048460479142288 2816389558961014111001500200030005000838 2111002182029123745951206716066243563277 0111000154772103241100599971450007500100 00104000111000162000166000219000237000 324243-Pole Size 1 Contactors3-Pole Size 3 ContactorsRelaysElectronic TimersIndicating Lights60998836283097806203628 Totals3111773 Industrial

10 CONTROL TransformersSelection Selection Inrush VA = = (VA Sealed) 2 + (VA Inrush) 2 9-4 1999 CONTROL POWERTRANSFORMERS When Ordering Specify n Catalog Number Description These CONTROL transformer kits pro-vide a convenient on-the-job addi-tion of CONTROL TRANSFORMERS to the following NEMA 1, 3R, 4/4X and 12 enclosed starters. Adding or chang-ing these kits does not affect the UL listing in most instances. For Non-combination Starters These kits may be used for trans-former voltage conversion on Free-dom NEMA, IEC and Advanced Design NEMA (Advantage) starters furnished from the factory with con-trol TRANSFORMERS installed.