Trane · model number decoder

Trane Precedent YSK/YHK/TSK/THK (R-454B)

Trane's R-454B Precedent rooftop, 3 to 25 tons, in cooling-only (TSK, THK) and gas/electric (YSK, YHK) versions. The K in the third digit marks R-454B; the model number also gives efficiency, tonnage, voltage, heat and factory options.

Packaged rooftop, cooling only or gas/electric · 3–25 tons · R-454B

Model numbers starting TSK, THK, YSK or YHK.

Quick answers

Tonnage from the model number

YHK090A3S0M**D0B0010100A10000 is a 7.5-ton unit: characters 4–6, 090, are the nominal size.

036 = 3 tons 048 = 4 tons 060 = 5 tons 072 = 6 tons 090 = 7.5 tons 102 = 8.5 tons 120 = 10 tons 150 = 12.5 tons 180 = 15 tons 210 = 17.5 tons 240 = 20 tons 300 = 25 tons

Source: RT-PRC115F-EN, page 23.

Factory filters by tonnage

3 tons	(4) 20 x 20 x 2 in.
4–5 tons	(4) 20 x 20 x 2 in. TSK, YSK(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in. THK, YHK
6–10 tons	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.
12.5 tons	(3) 18 x 18 x 2 in. and (3) 24 x 18 x 2 in. TSK(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in. YSK(8) 20 x 24 x 2 in. THK, YHK
15–25 tons	(8) 20 x 24 x 2 in.

Source: RT-PRC115F-EN, pages 26, 29, 33, 37. Check the rack before ordering; filters get changed over the years.

Age from the serial number

The first two digits are the year and the next two the week it was built. 150500273D was built in week 5 of 2015. How to read it

Source: Trane Support article 44514808922893.

Sizes and filter sizes

Size code	Nominal tons	Return-air filters (TSK)	Return-air filters (YSK)	Return-air filters (THK)	Return-air filters (YHK)	Compressors
036	3	(4) 20 x 20 x 2 in.	(4) 20 x 20 x 2 in.	(4) 20 x 20 x 2 in.	(4) 20 x 20 x 2 in.	1 scroll
048	4	(4) 20 x 20 x 2 in.	(4) 20 x 20 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	1 scroll
060	5	(4) 20 x 20 x 2 in.	(4) 20 x 20 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	1 scroll
072	6	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	2 manifolded scrolls
090	7.5	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	2 manifolded scrolls
102	8.5	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	2 manifolded scrolls
120	10	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	2 manifolded scrolls
150	12.5	(3) 18 x 18 x 2 in. and (3) 24 x 18 x 2 in.	(2) 18 x 24 x 2 in. and (3) 24 x 16 x 2 in.	(8) 20 x 24 x 2 in.	(8) 20 x 24 x 2 in.	2 manifolded scrolls
180	15	(8) 20 x 24 x 2 in.	(8) 20 x 24 x 2 in.	(8) 20 x 24 x 2 in.	(8) 20 x 24 x 2 in.	2 manifolded scrolls
210	17.5	(8) 20 x 24 x 2 in.	(8) 20 x 24 x 2 in.	(8) 20 x 24 x 2 in.	(8) 20 x 24 x 2 in.	2 manifolded scrolls
240	20	(8) 20 x 24 x 2 in.	(8) 20 x 24 x 2 in.	(8) 20 x 24 x 2 in.	(8) 20 x 24 x 2 in.	2 manifolded scrolls
300	25	(8) 20 x 24 x 2 in.	(8) 20 x 24 x 2 in.	(8) 20 x 24 x 2 in.	(8) 20 x 24 x 2 in.	2 manifolded scrolls

Source: RT-PRC115F-EN, pages 23, 25, 26, 29, 33, 37. Factory filter sizes. Check the rack before ordering; filters get changed over the years.

Trane Precedent YSK/YHK/TSK/THK (R-454B) model number nomenclature

Example: YHK090A3S0M**D0B0010100A10000. Select a position to jump to its codes.

Y1 H2 K3 0904–6 A7 38 S9 010 M11 **12–13 D14 015 B16 017 018 119 020 121 022 023 A24 125 026 027 028 029

Position 1 Unit function

T	Cooling only (electric heat optional)
Y	Cooling with gas heat

RT-PRC115F-EN, page 23

Position 2 Cooling efficiency

S	Standard efficiency
H	High efficiency

RT-PRC115F-EN, page 23

Position 3 Refrigerant

K	R-454B

RT-PRC115F-EN, page 23

Position 4–6 Nominal cooling size

036	3 tons
048	4 tons
060	5 tons
072	6 tons
090	7.5 tons
102	8.5 tons
120	10 tons
150	12.5 tons
180	15 tons
210	17.5 tons
240	20 tons
300	25 tons

RT-PRC115F-EN, page 23

Position 7 Design sequence

A	Design sequence A (the only sequence in the August 2026 catalog's model tables)

RT-PRC115F-EN, page 185

Position 8 Voltage

3	208–230 V, 3 phase, 60 Hz
4	460 V, 3 phase, 60 Hz
W	575 V, 3 phase, 60 Hz

RT-PRC115F-EN, page 23

Position 9 Unit controls

S	Symbio 700 unit controller

RT-PRC115F-EN, page 23

Position 10 Heat type

0	Base model (no special heat type)
A	Gas heat with stainless steel heat exchanger
B	Modulating gas heat
E	SCR modulating electric heat
F	Hot water coil control (hydronic heat)

RT-PRC115F-EN, page 23

Position 11 Heating capacity (electric on T, gas on Y)

0	No heat
B	6 kW electric heat
C	9 kW electric heat
E	12 kW electric heat
G	18 kW electric heat
J	23 kW electric heat
K	27 kW electric heat
N	36 kW electric heat
P	54 kW electric heat
R	72 kW electric heat
L	Low gas heat
M	Medium gas heat
H	High gas heat

RT-PRC115F-EN, page 23

Position 12–13 Service sequence

**	Factory assigned. Trane does not publish a code list for these two digits.

RT-PRC115F-EN, page 23

Position 14 Fresh air

0	No fresh air
A	Manual outside air damper, 0–50%
B	Motorized outside air damper, 0–50%
C	Economizer, dry bulb, without barometric relief
D	Economizer, dry bulb, with barometric relief
E	Economizer, reference enthalpy, without barometric relief
F	Economizer, reference enthalpy, with barometric relief
G	Economizer, comparative enthalpy, without barometric relief
H	Economizer, comparative enthalpy, with barometric relief
K	Downflow low-leak economizer, dry bulb, with barometric relief
M	Downflow low-leak economizer, reference enthalpy, with barometric relief
P	Downflow low-leak economizer, comparative enthalpy, with barometric relief
R	Downflow low-leak economizer, differential dry bulb, with barometric relief

RT-PRC115F-EN, page 23

Position 15 Supply fan / motor

0	Multi-speed motor
1	Optional high static motor
2	Single zone VAV, standard motor
3	Single zone VAV, oversized/high static motor
4	Multiple zone VAV, standard motor
5	Multiple zone VAV, oversized/high static motor

RT-PRC115F-EN, page 23

Position 16 Service access / filters

0	Standard panels, standard filters
A	Hinged access panels, standard filters
B	Standard panels, 2 in. MERV 8 filters
C	Hinged access panels, 2 in. MERV 8 filters
D	Standard panels, 2 in. MERV 13 filters
E	Hinged access panels, 2 in. MERV 13 filters

RT-PRC115F-EN, page 23

Position 17 Condenser coil protection

0	Standard coil
1	CompleteCoat condenser coil

RT-PRC115F-EN, page 23

Position 18 Through-the-base provisions

0	None
A	Through-the-base electric
B	Through-the-base gas piping (Y models)
C	Through-the-base electric and gas piping (Y models)

RT-PRC115F-EN, page 23

Position 19 Disconnect / circuit breaker

0	None
1	Unit-mounted non-fused disconnect
2	Unit-mounted circuit breaker

RT-PRC115F-EN, page 23

Position 20 Convenience outlet

0	None
A	Unpowered 20 A convenience outlet
B	Powered 15 A convenience outlet

RT-PRC115F-EN, page 23

Position 21 Communications

0	None
1	Advanced controller with BACnet interface
3	Advanced controller with Air-Fi wireless interface

RT-PRC115F-EN, page 23

Position 22 Refrigeration system

0	Standard refrigeration system
A	Humidity control (modulating hot gas reheat)

RT-PRC115F-EN, page 23

Position 23 Controls expansion module

0	None
1	XM-30 expansion module
2	XM-32 expansion module
3	XM-30 and XM-32 expansion modules
4	Two XM-30 expansion modules
5	Two XM-32 expansion modules

RT-PRC115F-EN, page 23

Position 24 Smoke detector

0	None
A	Return air smoke detector
B	Supply air smoke detector
C	Supply and return air smoke detectors

RT-PRC115F-EN, page 23

Position 25 System monitoring

0	None
1	Clogged filter switch
2	Condensate overflow switch
3	Discharge air sensing tube
4	Clogged filter switch and condensate overflow switch
5	Clogged filter switch and discharge air sensing tube
6	Condensate overflow switch and discharge air sensing tube
7	Clogged filter switch, condensate overflow switch and discharge air sensing tube

RT-PRC115F-EN, page 24

Position 26 Not used

*	Not used. Trane lists no codes for this digit.

RT-PRC115F-EN, page 24

Position 27 Unit hardware

0	No enhancements
1	Stainless steel drain pan

RT-PRC115F-EN, page 24

Position 28 Short circuit current rating

0	Standard (5 kA) SCCR marking
A	Tier 2 (65 kA) SCCR marking

RT-PRC115F-EN, page 24

Position 29 Low ambient

0	None
A	Low ambient cooling to 0°F

RT-PRC115F-EN, page 24

How old is this unit? Reading a Trane serial number

Ten characters on light commercial units built since 2010. Positions 1–2 are the year, 3–4 the week, 5–9 a sequence number and 10 the plant letter: A Monterrey, D Clarksville, L Lynn Haven. Trane’s example 1505 00273 D was built in week 5 of 2015 at Clarksville.

Example: 150500273D

Positions 1–2: Year, two digits since 2010 (15 = 2015)
Positions 3–4: Week of manufacture
Positions 5–9: Sequence number
Position 10: Plant: A Monterrey, D Clarksville, L Lynn Haven

Source: Trane Support article 44514808922893. This is the manufacture date, not the install date.

Trane shows the position layout and plant letters in a diagram in the article; its text names the fields and lists the year codes. We read the positions from the diagram.
Units built 2002–2009 use a one-digit year and earlier units a year letter. Trane lists those codes but doesn’t show where they sit in older serials, so we only date the ten-character format used since 2010.
Trane’s year table prints 2019 as “10” and 2025 as “23”. We read both as typing errors: 19 is 2019 and 25 is 2025.

Serial number dates for every rooftop brand we cover →

Notes and limits

Covers the R-454B Precedent nomenclature in Trane's August 2026 catalog RT-PRC115F-EN, digits 1–29. Every model table in that catalog shows design sequence A; later sequences may add codes and will show as unknown.
One modulating gas heat row in the catalog prints YHK150B**BH where every other row, including other YHK150 rows, shows design sequence A. We treat it as a misprint and list only A.
Digits 12–13 are a factory-assigned service sequence with no published code list, and digit 26 is marked not used. Enter them as they appear.
THK and YHK are the high-efficiency units, not heat pumps. Precedent heat pumps use separate literature and are not decoded here.
Filter sizes are Trane's recommended factory throwaway filters from the general data tables. Where two sizes are listed, the unit takes both sets. Standard and high efficiency units of the same tonnage can take different filters, and at 12.5 tons the TSK150 table lists different filters from the YSK150. Confirm against the rack in the unit.
The R-410A Precedent uses C in the third digit (TSC, THC, YSC, YHC) and has its own page. The catalog does not say which R-410A models these units replace.
No serial-number date decoder: Trane's catalog does not describe the serial format.

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BoltWright put this page together from the manufacturer’s published documents, and we aren’t affiliated with Trane. Check the unit’s nameplate and the current Trane literature before you order parts.

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