[BS]: 政府MPS point32嘅BS工程師面試會問啲乜？

話說政府只有Housing Authority房屋署或Electrical and Mechanical Services Department機電工程署會請已考咗牌嘅BS工程師。聽聞取錄率極低(<3%)，兼且consultant出身、後生、靚女係佔盡優勢。由於呢種面試經驗好少，簡單地分享一下﹕

入到去大概面試半個鐘。有左、中、右三個人真係比分。左邊嗰個係Senior Engineer問MVAC+Fire；中間嗰個係Chief Engineer問Renewable相關；右邊嗰個Senior Engineer問電。

開始嗰陣有五分鐘presention講你咁耐以嚟响邊度做過有啲乜經驗, present嗰啲嘢其實冇乜用因為佢地完全冇問過。

          中間嗰個開始用英文問Renewable﹕

1. 燒屍室(係英文問，到今日都未識呢個字)嗰啲廢熱可以點用？一開波就被個唔識嘅英文字拋疾，佢見我唔識呢個英文字，好在都有大概解釋下話係"the place that burn a dead body", 咁講完後就明佢想問乜。先答可以有兩個用途，一個係可以用嚟做Absorption Chiller, 呢種Chiller 同普通Chiller 最唔同既地方係佢唔係用Compressor, 而係用廢熱regenerate啲Lithium Bromine; 同埋可以用嚟煲熱水做perimeter zone terminal reheat;

2.  問﹕由於呢種Chiller 個供熱要穩定，你有啲乜對策？答曰﹕我會並聯熱水系統，heat exchanger + heater + pump, 煲住啲水，如果唔夠熱既時候就開heater確保穩定熱水供應；

3. 問﹕有冇諗過攞呢啲廢熱嚟產生電力？答曰﹕有，有一種叫thermalelectric generator, 跟據thermal dynamic 2nd law, entropy = delta Q/T, 熱水對常溫水之間有delta Q可以用嚟制造電壓差從而生成電流，大概係反制冷片原理，但據我所知好少會咁用因為效率太低；呢種嘢可以大概理解為平時冷熱水機用嗰啲制冷片，用電分開一個close system嘅冷同熱，而呢個thermalelectric generator就係呢個原理反返過嚟用冷熱差做電勢差； (答到呢度中間嗰個Chief Engineer話good表示滿意) 跟住右邊Senior Engineer問EL:

4. 泳池燈光設計有啲乜要點？答日﹕跟據Food and Environmental Hygiene Department 個design standard, 要求池底燈少過25V, 同埋响泳池既任何一點個lux level 要最少200lux with UPS;

5. 咁如果係比賽池如奧運要做TV轉播，個燈光要求又係點？答曰﹕Sorry泳池燈光要求我真係唔識。但我知道如果係草地大球場做TV轉播，跟據UEFA lighting design guideline, 起碼要1000-1500lux; colour rendering 要大過75, 一般用80; uniformity 大概0.8, colour temperature 唔能夠用黃光而係要白光，大概5000或以上。同埋要注意打燈個入射角，大概係25度-45度唔好妨擬到比賽者；

6. 除此之外仲有啲乜燈光要注意？答曰﹕要分兩組，一組平時開，另一組比賽先會開；

7. 做energy audit 嗰陣發現有條cable copper loss out of BEEO requirement, 你會點解決？答曰﹕唔好意思我唔識，我暫時淨係諗到成條換咗佢，未諗到其他方案，我都知呢個唔係一個好既方案太浪費；
   
   最後係左邊Senior Engineer問AC+Fire:

8. 比一間醫院你，cooling load 5000 tons, 啲chiller 你會點design? 大前提係冇sea water cooling. 答曰﹕我會睇下有幾多係essential loading例如比手術室、隔離病房等，如果比office的話，我會揀water cool; 如果係essential loading 的話，我會比air cool, 因為water cool部件相對多，多個香爐多隻鬼，越多部件越唔可靠；

9. 佢﹕而家有1000tons 係non essential, 有4000tons 係essential, 你會點比chiller? 答曰﹕Sorry我用慣kW, 當然我知kW to tons is 3.517, 我要轉轉單位，跟住我即响張白紙度mark. 我話air cooled chiller max. capacity 大概係1500kW, 我會分十幾台派比essential load, 兼且係全部equal size, in order to easy operation and maintenance, also easy storage of spare parts; for non-essential, 我會用兩大一細unequal size, optimize energy use, 細機响low loading 嗰陣行；

10. 咁你有啲乜energy efficiency strategy for air-cooled chiller? 答曰﹕我會用oil free magnetic bearing + VSD for compressor;

11. 條decoupler點size? 請你而家即刻劃張water side schematic 說明。即場畫咗張decoupler schematic出嚟後 ，我話primary loop pipe size 大概係比secondary loop 大5%；

12. 佢跟住問fire, 問醫院經常有false alarm, 你點解決？對曰﹕話說smoke detector主流兩大種，一種係ionization type, 一種係optical type. ionization type 係通過放射元素keep住射一束alpha粒子出嚟ionization從而產生電流，當有煙block咗佢後就冇電流，從而踢著個FS Signal；另一種係optical type 係射束光出嚟再反射返去個receiver度接收，同樣當有煙block就起訊號。有research paper 講話optical type 個false alarm 概率低啲；

13. 再問﹕除此之外，响O&M上仲有乜手段可以解決False alarm? 對曰﹕唔好意思，我真係諗唔到；(答案詳見<Smoke head false alarm有啲乜解決辦法？>)

14. 問﹕响醫院度有病人投訴chiller嘈，有啲乜對策？答曰﹕我會考慮用floating slab. 再問﹕如果間醫院已經起好咗又點？答曰﹕我會加acoustic panel enclouser包起佢，同埋會响佢坐住嗰塊interia block and spring埋手optimize;

大概就係咁，當然中間仲有唔少嘢係miss咗記漏。最終呢次面試係勉強合格，但合格同正式聘用係兩回事嚟。

以下係EMSD嘅面試計分方法﹕

Qualities/Competencies Assessed	Max. Marks	Passing Marks
1. Relevance of Experience Experience related to the duties of the job	25	12.5
2. Professional knowledge Professional knowledge in Building Services Engineering	25	12.5
3. General Intelligence Logical and perceptive thinking and potential for development	10	5
4. Disposition Confidence, reliability and maturity	10	5
5. Attitude Initiative, dependability and manner	10	5
6. Oral Expression (i) Fluent command of Cantonese (ii) Fluent command of English	5 5	2.5 2.5
7. Basic Law Test Basic Law Test result (Degree / Professional Grades)	10	-

以下係Housing嘅計分方法﹕

Description	Full Marks	Passing Marks
(I) Interview (i.e. 90% of the Overall Assessment)
1. Professional knowledge	30	15
2. General analytical and judgment skills	15	7.5
3. Communication and presentation skills	15	7.5
4. Job knowledge	15	7.5
5. Management skills, motivation and potential for development	10	5
Total for (I):
(II)(a) Basic Law Test Result	10	-
(III) Bonus score: With valid Registered Professional Engineer Status (BSS/ELL/MCL)	5	-

佢地一般都係先打個總分比你，然後先再後推寫返你每項嘅細分，即係總體印象先係最重要。正如之前所講，如果你係A字頭之類嘅大顧問出身又夠後生的話，已經贏咗一半；再加埋係女仔兼靚女的話，就贏埋之後嗰半。亦即是話，如果你唔係顧問出身，又年近四十，大可以慳返啖氣唔洗搏入政府，畢竟私人市場繼續做上去一樣可以十幾萬個月，唔會比入政府差。

我估計成個blog加埋大概cover到呢類BS technical面試0.5%嘅問題，亦都見得政府BS工程師面試問嘅嘢正路過香港考BS牌好多。BS嘅知識係可以用學無止境嚟形容。