1、 Manufacturing StandardsFord Motor Company199212 POWER SOURCES FOR EQUIPMENT - LIGHTING EW3AND ACCESSORIESEngineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 1 of 31. SCOPE:1.1 This standard describes acceptable 120 VAC power sources, commonlyreferred to as Lighti
2、ng Transformer Disconnects (LTDs) forauxiliary electrical apparatus which is part of production machinesand industrial equipment. Examples of auxiliary apparatus include,but are not limited to, work lights on machine or other industrialequipment, lights within the main electrical control enclosure,
3、anisolated power source for programmable controllers and relatedaccessories, and instrumentation.1.2 GENERAL:1.2.1 Wiring of lighting circuits and other details shall conform tosection E10.2 as specified in Ford Manufacturing Standard EX1.1.2.2 Fuses specified in paragraph 2.1 shall be sized for the
4、transformer furnished. See Table 4-5 in Standard EX1.2. LIGHTING SYSTEM SOURCES:2.1 BASIC REQUIREMENTS: The 120 VAC power source for the lamp or lampsand receptacle(s) in the control enclosure and/or on the industrialequipment, shall be obtained from a 480/120 volt transformer. Thepower for the tran
5、sformer shall be taken from the LINE side of themain disconnecting means on the control panel. A two-pole disconnectswitch shall interrupt the primary winding of the transformer, andshall be capable of being locked ONLY in the OFF position, usinglocks described in Ford Standard ES20. Escutcheon plat
6、es or othersuitable means shall be provided to clearly indicate the positionsof the operating handle, with the words “OFF“ and “ON“ in 1/2-inchhigh letters with an Arrow in the Off direction as a minimum.Overcurrent protection shall be provided in both primary leads withtype ATM or FNQ fuses or equa
7、l, and in one secondary lead with a250V, type FNA or equal, dual element fuse. The other secondary leadshall be grounded in an approved manner.2.2 ASSEMBLY: The transformer, disconnect switch, fuses, and allterminals shall be mounted in a NEMA Type 1 enclosure with hingeddoor or in a NEMA 12 enclosu
8、re for externally mounted LTDs. Thedoor swing shall be to the left and not exceed 90 degrees. A yellowplate with black lettering shall be affixed to the door which reads:CAUTION: WIRED TO LINE SIDE OF MAIN DISCONNECT. The plate shallconform to Standard EX1, 2.12.1. The disconnect switch shall bemech
9、anically interlocked with the door of the LTD enclosure, so thedoor cannot be opened with the switch in the “ON“ position. Damageshall not occur to the disconnect switch or its handle mechanism ifthe door is swung shut with the switch inadvertently moved to the“On“ position. The terminals on the lin
10、e side of the disconnectManufacturing StandardsFord Motor Company199212 POWER SOURCES FOR EQUIPMENT - LIGHTING EW3AND ACCESSORIESEngineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 2 of 3switch if accessible, shall be covered with a removable insulatingmaterial, a
11、nd all other components shall be so arranged that, whenthe enclosure door is open, there are no live, current-carryingparts exposed.2.3 TRANSFORMER: The transformer furnished shall be a machine tool typeand comply with the requirements outlined in Standard EX1, paragraphE6.1.3 and E6.1.3.1.3. AUXILI
12、ARY POWER SOURCES:3.1 The 115 Vac power source for auxiliary apparatus shall meet therequirements of part 2 above except as follows:A. If the transformer secondary is specified ungrounded, bothsecondary leads shall be protected by the type FNA fuses.B. When specified a receptacle shall be furnished
13、and mounted inthe cover of the NEMA 1 enclosure. The receptacle shall be oneof the following:1. NEMA configuration 5-15R, heavy duty, duplex type.2. NEMA configuration 5-15R, heavy duty, single receptacleprotected by a ground fault circuit interrupter (GFCI).3. Russell and Stoll Number 8003N.4. Othe
14、r, as specified.3.2 MOUNTING & WIRING:3.2.1 Power sources for auxiliary purposes (LTDs) shall be mountedon the control panel subplate, behind the same door as the maindisconnecting means.Exception: LTDs containing transformers 2000 VA and largershall be mounted outside, or have the transformer porti
15、onoutside, the main control enclosure. All externally mountedLTDs or transformers shall have a NEMA 12 rating.3.2.2 The 480 VAC primary wiring to the LTD shall be individual blackwires, isolated from all other panel wiring, and encased inapproved orange, nonmetallic conduit which is connected to the
16、LTD with an approved metal fitting (the end by the maindisconnect being left open). The nonmetallic conduit shall besecured in place across the panel subplate using screws andscrew-type, adhesive cable tie mounting bases.3.2.3 All 120 VAC secondary wiring from the LTD shall be individualManufacturin
17、g StandardsFord Motor Company199212 POWER SOURCES FOR EQUIPMENT - LIGHTING EW3AND ACCESSORIESEngineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 3 of 3yellow wires, or yellow STO cable for lighting circuits - atthe specifying activitys written option. If STO cable
18、 isused the white wire shall be connected to the grounded side ofthe LTDs 120 VAC circuit. Individual white wires shall NOT beused for any circuit. Secondary wiring shall exit the LTDenclosure through insulated conduit bushings and be routedthrough plastic panel wireways inside the control enclosure tothe extent possible.3.2.4 GROUNDING & BONDING: The LTD enclosure shall be grounded orbonded as specified in Standard EX1, section 15.
