Bradford-White Corp MII120(A)-*-**-(SF manual

Save this manual for future reference Manual 238-47174-00B SERVICE MANUAL Troubleshooting Guide and Instructions for Service (To be performed ONLY by qua lified servi ce providers) Models Covered by This Manual: MII50(A)-*-**-(SF,CF,SCF)-*** MII80(A)-*-**-(SF,CF,SCF)-*** MII120(A)-*-**- (SF ,CF,SCF)-*** *Denotes kW Rating **Denotes Warranty Years *[...]

Tabl e of Con ten ts Page Service Proce dure I ntroducti on …………………………………… ……………………………… …. 2 - - - Tools………… ……………… ……………………………… …………………… 2 - - - G eneral Informati on ………………… ……………… ………………………[...]

G ENERAL INFORMATION Bradford Wh ite MII Se ries Commerc ial Elect ric water heaters can be m anufactu red with a cho ice between tw o differen t type s of thermosta t contro l optio ns as follows: Surface M ounted Therm ostats . I mmersi on Th ermostat (contact or model s). The model numbe r is coded to ide ntify the spec ific thermost at contr ol[...]

Page 4 G ENERAL INFORMATION Upper Control Bo x L owe r Control Bo x Grou nd L ug Ter mina l Blo c k F use Bl oc k (s) C ont act or( s) Hi gh Li mit ( ECO ) Cont rol Imme rs io n The rm ost at Control High Limit (ECO) Di rect I mmersi on Bulb The rmos ta t D irect Im mersion Bulb He ati ng El ement s C ont ac to r Mod el s Ge ner al Co ntr ols Lay o[...]

Page 5 GENERAL INFORMATION Upper Control Box Low er Control Box G ro und Lu g T ermin al Bl oc k C ont act or( s) S urf ace T her mos ta ts He at ing E lem e nt s H igh L im it ( ECO) C on trol 600V Surf ace Thermo stat (w/ Contacto rs) Mo dels General Controls Layo ut 5[...]

G ENERAL INFORMATION Pa ge 6 Sur face Mo unted Ther mostat s M anua l ECO (hi gh lim it) Rese t b utt on Temp eratu re c on tro l Dial S urf ace Mo unt C omb in at ion T he rm os ta t/ ECO (hig h limit) 89T S eri es Surface m ounted therm ostats ar e mounte d into a bracket abo ve each hea ting elem ent. The brack et holds the thermost at agains t [...]

GENERAL INFORMATION Pa ge 7 Surfa ce Mo unted Thermo stats (w/C ont actors) fo r 600V Models 600V m od els u se cont act ors t o de liver line v oltage to t he heating el ements. Ho wever, rather t han the i mmersi on t ype high limit and the rmostat de vices, surfac e mounted therm ostats ar e used to operate the cont rol circ uit of the water hea[...]

G ENERAL INFORMATION Con tac tor 1-½ ” He x Screw -in Flange Term inal Blo ck Screw Ter mina l Blo c k Zi nc Pl at ed Co pp er o r Inco loy Shea th El ement Rat ing I nk St am ped on side o f T erm inal B loc k. Direct Immersion “Screw-in ” Type Heat ing Eleme nt 0642 4500W 240V RC02 404524 Page 8 Cont ac t o r oper at ion is ac hiev ed by e[...]

G ENERAL INFORMATION Wat ts V olts x 1.732 W atts = Amps x Volts Volts Watts 2 Co mmon ly Used Fo rmul as 240V 1 Ph Ungr ounde d Ungr ounde d Ground ing BLACK RED GREEN 240 120 Co mm on Se rvi ce Wire Con fig ur ati ons Page 9 120 ( balanced 3 phase) A mps = Wat ts Volts (Single phase ) Amps = O hms = 120 ABC N eutral RED BLACK RED 120 120 208 208 [...]

S EQUENCE OF OPERATION MII Series Com merci al Electric Water Heate rs can use eith er immers ion thermo stat ( con tactor mode ls) or surface m ounted thermostats . Sequence o f operati on for each co nfigur ation is exp laine d below. It wou ld be imprac tical to show all wire di agram s applicable t o both configu ratio ns. A “typ ical wiring [...]

S EQUENCE OF OPERATION Sequence of Op eration: Surface Mou nted Ther mostats. OR Te rmin al Bloc k F us e Blo ck L in e Vol tag e Hea ti ng E lem en t Sur face Mount ed Thermo st at Line v oltage is a pplied acros s termina ls of fuse bloc k or a term inal bloc k. Line voltage cont inues down and conne cts to sur face mount ed thermost at s at term[...]

SEQUENCE OF OP ERATION Sequence of Op eration: 600V Surface M ounted Therm ostats (w/Contactors). Line vol tage is ap plied acros s ter minal s of fus e bloc k or a termina l block . Line voltage c ontinue s down and conn ects to ter minals L1, L2 & L3 of one or mor e contactors . A) Cont actor is open (no call for heat ), so there is no voltag[...]

T ROUBLESHOOTING Most com mon cause for improper electric wa ter h eater oper ation can be li nked to he ating elem ent failure. When troubles hooti ng an elect ric water heater wi th the incidenc e of “No Hot Wat er” or “Insuf fic ient Amount of Hot Water” It is alwa ys a good idea t o check the heati ng element s firs t followi ng the pro[...]

SYMPTOM P ROBABLE CAUSE CORRECT IVE ACTION No Hot Water 1. N o power to he ater . 2. B low n wat er he ate r fus es . 3. Lo ose w ire c onnec tio ns. 4. I noper ati ve heat ing el em ents . 5. I noper ati ve th ermo stat (s) . 6. Ope n EC O. 7. Ino pe rat iv e co nta c tor (s). 1. I noper ati ve heat ing el em ent. 2. S edime nt or lime b ui ld up [...]

SERVICE PROCED URE MC E- I Heating Element Tes ting 1. STOP, DANGER! Tu rn power “OFF” to water heat er. 2 . Remove acce ss cover from lower contro l box. Remove ins ulatio n from insi de of contr ol box. 3. Disconn ect wires fr om heati ng element . 4. Set multi-m eter to “ohms” se tting. 5. Touch pro bes of multi -meter to sc rew terminal[...]

SERVICE P ROCEDURE MC E-II Line Voltage Testing Page 1 6 Line Vol ta ge Te st ing Il lus tra tio n 3 1. STOP, DANGER! Tu rn power “OFF” to water heat er. 2. Open upper co ntrol pa nel door. 3. Determ ine connect ion poin t for line vol tage from ser vice panel, ter mi nal bl ock or fuse b lock 4. Se t mul ti-meter to volts A C. Be sure to scale[...]

SERVICE PROCE DURE MCE- III Fuse Tes ting Fus e Te stin g 1. Turn “OFF” power to water heat er. 2. Open upper co ntrol box t o allow access to f use block. 3. Locate fuse blo ck and rem ove fuses. 4. Set multi- meter t o the “Ohms” setti ng. 5. Check conti nuity acr oss fuse (see illu strat ion 5). A) Continu ity IS presen t, fuse is okay .[...]

SERVICE PROCED URE MCE-IV High Limit (ECO) Te sting Page 1 8 1. Th is pro cedur e a ssumes line volt age and fuses are in wor king order . 2. Th is pro cedure i llust rates testing o f just one surface th ermost at. Repea t this proced ure for all surface th ermost ats on the unit . 3. Tu rn po wer “O FF” to water heater. 4. Remove lower c ontr[...]

SERVICE PROCE DURE MCE- V High Limit (ECO) Te sting Page 1 9 1. Th is pro cedure a ssumes line volt age, transform er, fuses , and thermostat are in wor king orde r. 2. Tu rn po wer “O FF” to water heater . 3. Remove lower cont rol box cover and rem ove insulat ion fr om i ns ide of c on tr ol b ox . 4. Check for cont inuit y across te rminal s[...]

SERVICE PROCED URE MC E- VI High Limit (ECO) Te sting Page 2 0 High Limit Control (ECO) Testin g for Con tac tor M od els 1. Determine if Hi -Limit has actua ted. Thi s can be done by simply depre ssing t he reset butt ons. If yo u hear and/o r f eel a small clic k, the switch has actuat ed. 2. Use cauti on and turn pow er on to water heat er and o[...]

SERVICE P ROCEDURE MCE- VII Thermostat T esting Il lus tra tio n 8 Wa ter In Ta nk Is C old Wit h Po w er ON. 1. This pro cedure assumes line volt age, ECO and elemen ts are in w orki ng or der. 2 . TURN O FF POWE R TO WAT ER HEATER. 3. Remove acce ss cover from lower cont rol box. Remove ins ulatio n from insi de of contr ol box. Remove plastic co[...]

SERVICE PROCE DURE MCE- VIII Thermostat Testing Wa ter In Ta nk Is C old Wit h Po w er ON. 1. Th is pro cedur e a ssumes line volt age , ECO, tr ansformer ther mostat, and ele ments ar e in worki ng order. 2. TURN O FF POWE R TO WAT ER HEATER. 3. Remove acce ss cover from lower cont rol box. Remove ins ulatio n from insi de of contr ol box. 4. Usin[...]

SERVICE PROCED URE MCE-IX Thermostat T esting Immers ion Thermos tat Operat ion Test ing The r mosta t Con tr ol C onti nu ity Te st in g. 1. Thi s procedure assum es line voltage, ECO an d contact or(s) are in work ing order. 2. STOP, DANG ER! Turn p ower “OFF ” to wat er heater . 3. Remove l ower co ntrol box cover a nd i nsulat ion. 4. Loca [...]

SERVICE PROCE DURE MCE- X Contactor Testing Contact or Operati on Testi ng Noisy or chat teri ng contactor operat ion in most cas es is due to voltage v aria tions bei ng suppli ed to the water heat er. E xtended per iods of volt age v ariations will cause damag e t o the oper ating coil of the c ontacto r c ausin g nois y ope rati on. Deter mine t[...]

SERVICE PROCE DURE MCE- X Contactor Testing Page 2 5 Contac tor Opera tion Testing (continu ed) This proce dure assumes co ntrol circuit is operating co rrectly. Provi ding t he w ater t e mperatu re in ta nk i s within t he operating range of the the rmost at, chec king conta ctor oper ation can be as sim ple as rota ting t he thermo stat di al an[...]

SERVICE PROCED URE MC E- XI Thermostat R emoval and Re placement Front View Ther mos tat M ounti ng Surface Mounted Ther mostat Removal 1. STOP, DANGER! Tu rn power “OFF” to water heat er. 2. Remove acce ss cover from lower cont rol box. Remove ins ulatio n from insi de of contr ol box. Remove plastic cover f rom therm ostat. 3. Disconn ect wir[...]

Immersio n Thermost at Remova l & Re placemen t 1. STOP, DANGER! Tu rn power “OFF” to water heat er. 2. Tu rn of f cold water suppl y to he ater. Co nnec t hose to drain spigot of water heater an d route to an o pen d rain. Op en a nearb y hot wat er fauc et to vent heat er for drain ing. Op en drain s pigot of water he ater and allow h eat[...]

SERVICE P ROCEDURE MCE - XIII C ontactor Model High Limit (ECO) Contr ol Removal and Replacement Page 28 Contactor Mod el High Limit (ECO) Con trol Removal an d Replaceme nt 1. STOP, DANGER! Tu rn power “OFF” to water heat er. 2. Tu rn of f cold water suppl y to he ater. Co nnec t hose to drain spigot of w ater heat er an d route to an o pen dr[...]

SERV ICE PROCEDURE MCE-X IV 6 00V Model High Limit ( ECO) Control Removal and Replacement Page 29 600V Surface Th ermost at Model Hig h Lim it ( ECO) Con tr ol Removal an d Replacem ent 1. STO P, D ANGE R! Tu rn po wer “OF F” to wat er he a ter . 2. Remove lower c ontr ol box cover and insul ati on. 3. Locate high li mit s witch mount ed to the[...]

SERVICE PROCE DURE MCE- XV H eating E lement Removal and Replacement Heating Ele ment Removal 1. STOP, DANGER! Tu rn power “OFF” to water heat er. 2. Tu rn of f cold water suppl y to he ater. Co nnec t hose to drain spigot of w ater heat er an d route to an o pen dra in. Op en a nearb y hot wat er fauc et to vent heat er for drain ing. Op en dr[...]

Page 3 1 WARNING He ater co mponents and stor ed water may be HO T when per forming the fo llowing step s in this procedure. T ake nece ssary preca ution to p revent pe rsonal inju ry. SERVIC E PRO CEDUR E MCE- XVI Anode Inspection and Replacement Anode Insp ection and Repl acement 1. Tu rn powe r “OFF ” to wat er heate r. 2. Tu rn off cold wat[...]

Page 3 2 G eneric Part s List 32[...]

G eneric Part s List Item D esc rip tion 1 Anode . 2 Hot Water Outl et Nipple. 3 T&P Nippl e. 3A T&P Coupl ing. 4 T&P Reli ef Valve. 5 High L im it Swit ch. 5A Surf ace Hi gh Limit Switc h. 6 Hex Nut 7 Lock Washer 8 Screw 9 High L imit Spacer. 10 Cleanou t O-Ring . 10A Cleanout Gasket (A SME). 11 Cleanout Cover . 11A Cleanout Cover (AS [...]

NOTES Pag e 34 34[...]

NOTES Pag e 34 35[...]

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